Diaphragm Seal Pressure Transmitters

Diaphragm Seal Pressure Transmitters work with Diaphragm Seals for those harsh working conditions. The purpose of the diaphragm seal is to isolate the pressure sensor from the process medium.

Diaphragm Seal Pressure Transmitters

The diaphragm seal makes measuring pressure safer and more reliable. It is ideal for protecting pressure process transmitters even under harsh working conditions. The diaphragm seal can isolate the pressure sensor from the process medium. No matter absolute pressure or differential pressure measurement. Mounting with capillary and flange, Diaphragm Seal pressure transmitter can measure pressure, liquid level and flow.When the environment is extremely hot or cold, or when the process connection is difficult to connect to the measuring instrument. When the measured medium is corrosive, sticky, sticky or easily cured. Or when the process is not chemically compatible with the instrument material. It is recommended to use a diaphragm seal.

Sino-Inst offers a variety of Diaphragm Seal Pressure Transmitters for industrial pressure measurement. If you have any questions, please contact our sales engineers.

Featured Diaphragm Seal Pressure Transmitters

Flush diaphragm pressure sensor
Sanitary Pressure Transmitter
Diaphragm Seal Pressure Transmitter
Remote Diaphragm Seal Pressure Transmitter
Flange Mounted Differential Pressure Transmitter
Extended Diaphragm Seal DP Level Transmitter
Remote Seal Differential Pressure Transmitter
Differential pressure(DP) level transmitter

What is a diaphragm seal?

Diaphragm seals, also known as chemical seals or remote seals, are used for pressure measurements when the process medium should not come into contact with the pressurised parts of the measuring instrument.

A diaphragm seal has two primary tasks:

  1. Separation of the measuring instrument from the process medium
  2. Transfer of the pressure to the measuring instrument

You may like: Diaphragm pressure gauge

Advantages of diaphragm seals

Diaphragm seals offer the advantage that the “contact surface” between pressure medium and diaphragm is relatively large. Thus ensuring accurate pressure measurement, especially for very low pressures (< 600 mbar). Furthermore, they can be easily dismounted, e.g. for cleaning or calibration purposes.

Rosemount 1199

Rosemount 1199 remote transmission diaphragm system provides the world’s most extensive product variety and specifications to meet the requirements of various measurements and applications.

There are the following types of remote transmission differential pressure / level transmitters:
1) PFW flat type remote transmission device
2) RTW thread installation type remote transmission device
3) EFW inserted barrel remote transmission device
4) RFW flange mounted remote transmission device
5) SCW hygienic remote transmission device

The 1199 remote diaphragm can be assembled to Sino-Inst differential, gauge, and absolute pressure transmitters and liquid level transmitters.

We can learn more about Rosemount 1199 remote diaphragm.

How do diaphragm seals work?

Basically, diaphragm seals are used in all pressure measurement processes to avoid direct contact between the measuring instrument and the medium during this process.

In addition, if the measuring point cannot be installed or read because the measuring point is located in a hard-to-reach location, a diaphragm seal can also be used.

In both cases, the applied pressure is transferred to the measuring instrument through the system fill fluid in the diaphragm seal housing.

The diaphragm of the seal can be made of different materials, such as stainless steel, Hastelloy, Monel or tantalum. In addition, coatings with ECTFE, PFA or gold can also be used.

We can provide the best diaphragm seal design, materials, system fill fluid and accessories for each application. The combined configuration of the pressure measuring instrument and the diaphragm seal is mainly determined by the special application conditions of the diaphragm sealing system.

You may like: How does a pressure transmitter work?

Differential Pressure Transmitter Installation Guide

Diaphragm type pressure transmitter working principle

Diaphragm pressure transmitter is an automated instrument that measures fluid pressure in the industrial field.

  • It is mainly composed of pressure measuring probe, capillary tube, filling liquid and pressure transmission head.
  • One end of the pressure measuring probe is provided with an elastic metal diaphragm
  • When the pressure acts directly on the surface of the measuring diaphragm, the diaphragm will have a slight deformation.
  • The high-precision circuit on the measuring diaphragm transforms this tiny deformation into a highly linear voltage signal proportional to the pressure and also proportional to the excitation voltage.
  • Then use a special chip to convert this voltage signal into an industry standard 4-2OmA current signal or 1-5V voltage signal.
  • Because the measuring diaphragm adopts standard integrated circuit, which contains linear and temperature compensation circuits, it can achieve high precision and high stability.
  • The transmission circuit adopts a special two-wire system chip, which can ensure the output of a two-wire 4-20mA current signal, which is convenient for field wiring.

Read more about: What is industrial pressure transmitter?

When to use diaphragm seal ?

The diaphragm seal pressure transmitter is suitable for the following working conditions:

  1. The high temperature medium needs to be isolated from the transmitter.
  2. The measuring medium has a corrosive effect on the sensitive components of the transmitter.
  3. Suspended liquid or high viscosity medium.
  4. The measured medium solidifies or crystallizes due to changes in the environment or process temperature.
  5. Replacing the measured medium requires strict purification of the measuring head.
  6. The measuring head must be kept clean and hygienic.
  7. Liquid level measurement of sealed pressure vessel.

Difference between bourdon tube and diaphragm pressure gauge:

Frequently
Asked
Questions

The remote seal is used to prevent the medium in the pipeline from directly entering the pressure sensor assembly in the pressure transmitter. It is connected to the transmitter by a capillary filled with fluid. As a result, they’re often used in refining, petrochemical, and chemical plants.

Diaphragm pressure gauge consists of a diaphragm isolator and a universal pressure gauge to form a system pressure gauge. The spring tube is evacuated by special equipment. And fill people with irrigation fluid. Seal it with a diaphragm. When the pressure P of the measured medium acts on the diaphragm, it deforms. The working fluid filled in the compression system makes the working fluid form a △ P equivalent to P, with the help of work. The conduction of the liquid causes a corresponding elastic deformation-displacement at the free end of the elastic element (spring tube) in the pressure meter. According to the working principle of the pressure instrument matched with it, the measured pressure value is displayed.

Diaphragm pressure gauges consist of a system of diaphragms and universal pressure gauges. Diaphragm pressure gauges and equipment are mainly connected with threaded connections, flange connections and sanitary clamps. Diaphragm pressure gauges are suitable for measuring the pressure of medium with strong corrosion, high temperature, high viscosity, easy to crystallize, easy to solidify, and solid floats, as well as occasions where the measurement medium must be avoided from entering the general-purpose pressure meter and to prevent the accumulation of sediment and easy to clean.

The characteristics of the filling fluid determine the performance of the sealing system to a large extent, both in response time and temperature to the heat dissipation conditions.
The initial consideration in choosing a sealed diaphragm to fill fluid is the media compatibility of the process.
Glycerin, silicone oil and halogenated carbon are the most commonly used sealed diaphragm filling fluids.
In general there are three ways to fill a diaphragm seal:
1. Filling a diaphragm seal after assembly of the seal to the instrument
2. Filling a diaphragm seal before assembly of the seal to the instrument
3. Filling a diaphragm seal with a capillary between the seal and the instrument

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Sino-Inst is a manufacturer of Diaphragm Seal Pressure Transmitters.

Sino-Inst offers over 20 Diaphragm Seal Pressure Transmitters at best price. About 50% of these are Pressure level Transducer, 40% are Differential Pressure transmitters, and 40% are Diaphragm Seal Pressure transmitters.
A wide variety of Diaphragm Seal Pressure Transmitters options are available to you, such as free samples, paid samples. 

Sino-Inst is a globally recognized supplier and manufacturer of Diaphragm Seal Pressure Transmitters, located in China. Sino-Inst sells through a mature distribution network that reaches all 50 states and 30 countries worldwide. Diaphragm Seal Pressure Transmitters products are most popular in Domestic Market, Southeast Asia, and Mid East. 

You can ensure product safety by selecting from certified suppliers, with ISO9001, ISO14001 certification.

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Remote Seal Differential Pressure Transmitter

Remote seal differential pressure transmitter is used to prevent medium from entering transmitter. The pressure sensitive diaphragm and the transmitter are connected by a capillary filled with fluid. It is used to measure the level, flow and pressure of fluids, gases or steam.

Remote Seal Differential Pressure Transmitter is often used as a tank level transmitter. The smart pressure transmitter is connected with a stainless steel flange by capillary. The pressure is sensed by a remote transmission device installed on a pipe or container. The pressure is transmitted to the body of the transmitter through the filling silicone oil in the capillary. Then The delta chamber and the amplifying circuit board in the main body of the transmitter convert the pressure or differential pressure to 4 ~ 20mA. The DC signal is output. It can communicate for the setting and monitoring by cooperating with the HART communicator.

Sino-Inst offers a variety of DP pressure transmitters for industrial pressure measurement. Connection with diaphragm seals. If you have any questions, please contact our sales engineers.

Features of Remote Seal Differential Pressure Transmitter

  1. Simulate the “online operation” assessment one by one. Ensure that the transmitter works stably and reliably under the extreme ambient temperature, medium temperature and working pressure (including positive pressure or vacuum).
  2. Adopt “dynamic profile” remote transmission diaphragm structure. The diaphragm will not be damaged after overload. The accuracy will not change after long-term work.
  3. The filling system with full fusion welding and rigid sealing structure is selected to eliminate the occurrence of oil leakage.
  4. Novelly designed capillary coupling parts. Capillary is reliably protected. It is not easy to break when used on site.
  5. Variety, form and size of remote transmission device. And a variety of filling liquid types. It can meet the measurement needs of various occasions.
  6. Various special products can be provided. Including high temperature, high vacuum, fast response and unequal length capillary (length ≤ 3 meters) remote transmission pressure transmitter

Specifications of Remote Seal Differential Pressure Transmitter

Output signal:4 ~ 20MA. DC two-wire system (analog) superimposes the digital signal on the two-wire 4 ~ 20mA DC signal, and the user selects linear or square root output.
Power supply:12 ~ 45V.DC;
Load characteristics:
Power supply impact: <0.005% output range / V;
Load effect: when the power supply is stable, there is no load effect;
Measurement accuracy: ± 0.1% of the adjustment range, ± 0.2% standard accuracy is ± 0.2%, if other accuracy is selected, please indicate when ordering and selecting;
Range ratio: 10: 1 or 100 to 1;
Resistance: usually adjustable from 0.1 to 16 seconds, when inert liquid is filled or with a remote transmission device, the time constant will increase;
Startup time: <2 seconds, no warm-up is required.

Working environment:
ambient temperature -29 ~ 93 ℃ (analog amplifier);
29 ~ 75 ℃ (digital / smart amplifier);
-29 ~ 65 ℃ (with display meter);
Ambient humidity 0 ~ 95%.
Protection characteristics:protection ability IP65;
Explosion-proof type: Flameproof Ex d II BT4-6;
Intrinsically safe Exia II CT5.
The effect of static pressure: Zero error: ± 0.5% zui large range limit, for 32MPa under pipeline pressure by zero adjustments.
Electromagnetic radiation effect:0.05% large range value, receiving radiation frequency 27 ~ 500MHz, test field strength 3V / m.
Indication table (%):LCD digital display accuracy ± 0.2%.
Vibration effect:± 200% / g when vibrating at 200Hz in any direction.
Installation position: The diaphragm is not installed vertically, and a zero error of less than 0.24KPa may occur, but it can be corrected by zero adjustment.
Weight: 3.9Kg (excluding accessories).

Note:
① The working pressure of the remote pressure transmitter also depends on the specifications of the selected flange.
② The working temperature of the remote transmission device is determined by the type of filling liquid selected.
③ The remote transmission pressure transmitter refers to the output change produced by the temperature of the remote transmission device on one side.
④ The effects of static pressure and temperature are measured during a large range.
⑤ The length of the capillary on the side of the GP remote pressure transmitter is generally 1.5 meters, and the length should not exceed 3 meters (special agreement is agreed).

Read more What is a diaphragm seal?

DP Remote Seal Pressure Transmitter with Diaphragm Seal Installation

Rosemount 1199 remote transmission diaphragm system provides the world’s most extensive product variety and specifications to meet the requirements of various measurements and applications.

There are the following types of remote transmission differential pressure / level transmitters:
1) PFW flat type remote transmission device
2) RTW thread installation type remote transmission device
3) EFW inserted barrel remote transmission device
4) RFW flange mounted remote transmission device
5) SCW hygienic remote transmission device

The 1199 remote diaphragm can be assembled to Sino-Inst differential, gauge and absolute pressure transmitters and liquid level transmitters.

We can learn more about 1199 remote diaphragm.

Read more about: Differential Pressure Transmitter Installation Guide

Applications of Remote Seal Differential Pressure Transmitter

Remote Seal Differential Pressure Transmitter is a pressure sensor assembly used to prevent the medium in the pipeline from directly entering the transmitter. It is connected to the transmitter by a capillary filled with fluid. It is used to measure the liquid level, flow rate and pressure of liquid, gas or steam. Then it is converted into 4 ~ 20mA DC signal output. The applicable media are as follows:

  1. Viscous medium at high temperature;
  2. Easily crystallized medium;
  3. Precipitation medium with solid particles or suspended matter;
  4. Strongly corrosive or highly toxic medium;
  5. It can eliminate the occurrence of leakage of the pressure guiding pipe and pollute the surrounding environment. It can be avoided when using the isolation liquid. Because of the unstable measurement signal.
  6. Continuously and accurately measure the interface and density;
  7. The remote transmission device can avoid the mixing of different instantaneous media. So that the measurement results truly reflect the actual situation of process changes;
  8. Places with high sanitation requirements;
  9. Such as in the production of food, beverage and pharmaceutical industries. Not only does the transmitter contact with the media meet hygienic standards, but it should be easy to rinse to prevent cross-contamination of different batches of media.

Extended reading: SI-703 Flush Diaphragm Pressure Sensor

Precautions for use:

In the use process, we should pay attention to consider the following situations:

  1. When measuring the liquid pressure, the installation location of the remote pressure transmitter should avoid the impact of the liquid (that is, the water hammer phenomenon). In order to prevent the sensor from being damaged by overpressure.
  2. When the remote pressure transmitter transmitter freezes in winter. The transmitter installed outdoors must take anti-freezing measures. Avoid expansion of liquid in the pressure port due to icing volume. Lead to sensor damage.
  3. When wiring, pass the cable through the waterproof connector (accessory) or the flexible tube and tighten the sealing nut. In order to prevent rainwater etc. from leaking into the transmitter housing through the cable.
  4. When the remote pressure transmitter is used to measure the liquid pressure. The pressure tap should be opened on the side of the process pipe. In order to avoid sedimentation and accumulation of slag.
  5. To prevent the flange liquid transmitter from contacting with corrosive or overheated media. It is also necessary to prevent scum from depositing in the duct;
  6. When measuring the pressure of the gas, the pressure port should be opened at the top of the process pipeline. And the flange level transmitter should also be installed in the upper part of the process pipeline. In order to quickly deposit the deposited liquid into the process pipeline.
  7. The remote pressure transmitter should pay attention to that the pressure guiding tube of the sensor should be installed in a place with small temperature fluctuation.
  8. When measuring the steam or other high temperature medium of the remote pressure transmitter, it is necessary to connect a condenser such as a buffer tube (coil tube). The operating temperature of the transmitter should not be exceeded.

Extended reading: Smart Differential Pressure Transmitter

Remote Seal Differential Pressure Transmitters Working Principle

What is a diaphragm seal?

Diaphragm seals, also known as chemical seals or remote seals, are used for pressure measurements when the process medium should not come into contact with the pressurised parts of the measuring instrument.

A diaphragm seal has two primary tasks:

  1. Separation of the measuring instrument from the process medium
  2. Transfer of the pressure to the measuring instrument

You may like: Diaphragm pressure gauge

What is remote seal?

The remote seal is used to prevent the medium in the pipeline from directly entering the pressure sensor assembly in the pressure transmitter. It is connected to the transmitter by a capillary filled with fluid. As a result, they’re often used in refining, petrochemical, and chemical plants.

What are the advantages of diaphragm seals?

Diaphragm seals offer the advantage that the “contact surface” between pressure medium and diaphragm is relatively large. Thus ensuring accurate pressure measurement, especially for very low pressures (< 600 mbar). Furthermore, they can be easily dismounted, e.g. for cleaning or calibration purposes.

How do diaphragm seals work?

Basically, diaphragm seals are used in all pressure measurement processes to avoid direct contact between the measuring instrument and the medium during this process.

In addition, if the measuring point cannot be installed or read because the measuring point is located in a hard-to-reach location, a diaphragm seal can also be used.

In both cases, the applied pressure is transferred to the measuring instrument through the system fill fluid in the diaphragm seal housing.

The diaphragm of the seal can be made of different materials, such as stainless steel, Hastelloy, Monel or tantalum. In addition, coatings with ECTFE, PFA or gold can also be used.

We can provide the best diaphragm seal design, materials, system fill fluid and accessories for each application. The combined configuration of the pressure measuring instrument and the diaphragm seal is mainly determined by the special application conditions of the diaphragm sealing system.

Diaphragm type level transmitter working principle

Smart differential pressure transmitters are often used to measure liquid level, flow rate, etc. Differential pressure transmitter cooperates with sealing diaphragm, capillary, etc.

The differential pressure type liquid level gauge uses the principle that when the liquid level in the container changes, the static pressure generated by the liquid column also changes accordingly, as shown in the figure.

For closed tanks. Set the bottom pressure to P. If the pressure on the liquid surface is P3 and the liquid level height is H, then:
P = P3 + Hpg (3-11)
In the formula: p is the medium density; g is the acceleration of gravity.
From the formula ((3-1 “available:
△ P = P-P3 = Hpg (3-12)
Usually the density of the measured medium is known, the pressure difference △ P is proportional to the liquid level height H. The pressure difference on the side will know the measured liquid level height.

When the container under test is open, the gas pressure is atmospheric pressure. The negative pressure chamber of the differential pressure gauge can be vented to the atmosphere. It is known that the pressure gauge can also be used to measure the liquid level at this time.

If the container is closed, you need to connect the negative pressure chamber of the differential pressure gauge to the gas phase of the container.

Pressure level transmitter is good for level measurement. Most of the time, we use submersible hydrostatic level sensor for the level measurement. When you can not use the probe of hydrostatic level sensor, you can try with this pressure level transmitter. Pressure level transmitter, is one type of DP level measure instrument, with the diaphragm.

More

SMT3151LT Differential pressure (DP) level transmitter a new type of differential pressure (DP) transmitter produced by advanced technology and equipment. Continuous level, flow and differential pressure measurement. Liquid level measurement, is the most common measurement process in continuous production processes, such as: petroleum and chemical industry. The liquid level measuring instrument currently widely used, is the differential pressure level transmitter.

More

In the case of open tanks or underground water wells, Hydrostatic pressure level transmitters are also suitable.

SI-151 Hydrostatic Level Sensor
SMT3151TR Hydrostatic level transmitter-Rod Type
SI-PCM260 Deep Well Water Level Sensor

FAQ

What is remote seal pressure transmitter?

Remote Diaphragm seal pressure transmitter with capillary is used as a level transmitter. Diaphragm Seals also called chemical seals, are used in applications where pressure sensor requires isolation from the process media. These applications are corrosive, high temperature, clogged. Or must sanitary fluids to remain in the pipeline or container. The pressure of the liquid in the process does not affect the pressure sensor. Instead, it is applied to the remote seal. And through the capillary, hydraulic pressure is transmitted to the pressure sensor. Installing and filling the diaphragm seal, the impact on instrument performance will be minimized. More

What is remote seal for level transmitter?

Remote seals are commonly used to protect pressure-measuring instruments including pressure gauges, pressure transmitters, and switches from hot, viscous, contaminated, or corrosive media. As a result, they’re often used in refining, petrochemical, and chemical plants. More Remote Diaphragm Seal System Pressure Transmitters

What is differential pressure transmitter working principle?

The basic principle of a differential pressure transmitter is to divide a space into two chambers with sensitive elements. When introducing pressure into the two chambers respectively. The sensor produces displacement (or displacement trend) under the combined action of the two pressures. This displacement is proportional to the pressure difference (differential pressure) between the two chambers. Convert this displacement into a standard signal output that can reflect the magnitude of the differential pressure.
A differential pressure transmitter is a transmitter that measures the pressure difference between the two ends of the transmitter. Output standard signals (such as 4 ~ 20mA, 0 ~ 5V). Differential pressure transmitters are different from general pressure transmitters in that they have two pressure interfaces. Differential pressure transmitters are generally divided into positive pressure end and negative pressure end. In general, the pressure at the positive pressure end of the differential pressure transmitter should be greater than the pressure in the negative pressure section to measure.
Extended Reading: Liquid pressure sensor

What is diaphragm seal pressure transmitter?

Diaphragm seal pressure transmitter with flange direct mount is good for level measurement. Diaphragm seals, also known as chemical seals or flush seals. Diaphragm seals work with pressure transmitter, pressure gauges. To prevent process medium from entering into the pressure-sensing assembly. So, Diaphragm seal systems protect pressure transmitters from hot, viscous, contaminated or corrosive media. Diaphragm seal connection can work with the capillary, flange and manufold. Like remote seal pressure transmitter, DP level transmitter. More

Extended Diaphragm Seal DP Level Transmitter
Extended Diaphragm Seal DP Transmitter is a level transmitter direct mounted on pipe or tank. The isolation diaphragm is in direct contact with the liquid medium.
Flange Mounted Differential Pressure Transmitter
Flange Mounted Differential Pressure Transmitter is also called single flange DP level transmitter. For liquid, gas or vapor pressure measurement.
Diaphragm Seal Pressure Transmitter
When the process medium should not come into contact with the pressured parts of the measuring instrument. Diaphragm sealed pressure transmitters are used for pressure measurement.
Remote Diaphragm Seal Pressure Transmitter
Remote seal pressure transmitter, with capillary and diaphragm seal, remote mount. Diaphragm seal systems protect pressure transmitters from hot, viscous, contaminated or corrosive media.



Extended Reading: Differential Pressure (DP) Flow Meters Technology

Sino-Instrument offers Remote Seal Differential Pressure Transmitters. A wide variety of Remote Seal Differential Pressure Transmitter options are available to you. Such as free samples, paid samples. Sino-Instrument is a globally recognized manufacturer of Pressure sensors, located in China. Sino-Instrument sells through a mature distribution network that reaches all 30 countries worldwide. Remote Seal Differential Pressure Transmitter products are most popular in Europe, Southeast Asia, and Mid East. You can ensure product safety by selecting from certified suppliers. With ISO9001, ISO14001 certification.

Request a Quote

Please enable JavaScript in your browser to submit the form

Extended Diaphragm Seal DP Level Transmitter

Extended Diaphragm Seal DP Transmitter is a level transmitter direct mounted on pipe or tank. The isolation diaphragm is in direct contact with the liquid medium.

Extended Diaphragm Seal DP Level Transmitter is a field level transmitter that is directly mounted on a pipe or container. The isolation diaphragm is in direct contact with the liquid medium. There is no need to lead out the positive pressure side with a pressure pipe. Therefore, it can measure the liquid level, pressure and density of high temperature, high viscosity, easy crystallization, easy precipitation and strong corrosion. Convert to 4 ~ 20mA. DC signal output.

The flanges are made of high-quality stainless steel materials such as 304 and 316. Wetted diaphragms are made of imported high-quality anti-corrosive materials such as 316L, Hastelloy C-276, Monel, and tantalum.

Sino-Inst offers a variety of DP pressure transmitters for industrial pressure measurement. Connection with diaphragm seals. If you have any questions, please contact our sales engineers.

Features of Extended Diaphragm Seal Differential Pressure Transmitter

  • Simple structure: There are no movable or elastic elements. Therefore, the reliability is extremely high. The amount of maintenance is very small.
  • Easy installation: The built-in structure especially shows this feature. No special tools are required.
  • Convenient adjustment: The two potentiometers of zero position and range can carry out zero point migration or range change at will within the effective range of liquid level detection. The two adjustments do not affect each other.
  • Widely used: Suitable for liquid level measurement of high temperature and high pressure, strong corrosion and other media.

Specifications of Extended Diaphragm Seal Level Transmitter

Measuring range:can be customized within the range of -4-4MPa (-10-10KPa, 0-50KPa, etc.)
Output signal: 4 ~ 20MA.DC two-wire system (analog). Two-wire system 4 ~ 20mA DC signal is superimposed with digital signal. Linear or square root output is selected by the user. (Smart)
Power supply:12 ~ 45V.DC
Range ratio: 10: 1 or 100 to 1
Power supply impact: <0.005% output range / V
Load effect: When the power supply is stable, there is no load effect.
Measurement accuracy: 0.1% of the calibration range. Standard accuracy is 0.2%. If other accuracy is selected, please indicate when ordering and selecting.
Resistance: usually adjustable between 0.1 to 16 seconds. When filling with inert liquid or with a remote transmission device, the time constant will increase.
Startup time: <2 seconds, no warm-up required
Working environment: ambient temperature -29 ~ 93 ℃ (analog amplifier)
 -29 ~ 75 ℃ (digital / smart amplifier)
    -29 ~ 65 ℃ (with display head)
Environmental humidity: 0 ~ 95%
Protection characteristics: protection ability IP65
Explosion-proof type: Flameproof Exd II BT4-6. Intrinsically safe Exia II CT5
Static pressure effect:Zero point error (can be eliminated under static pressure)
Static pressure from 0 ~ 13.7MPa, ± 0.2% / 6.9MPa
 Static pressure exceeds 13.7MPa, ± 0.5% / 6.9MPa

Extended reading: Smart Differential Pressure Transmitter

Applications of Extended Diaphragm Seal DP Level Transmitter

Extended Diaphragm Seal DP Transmitter can measure the liquid level, pressure and density of high temperature, high viscosity, easy crystallization, easy precipitation and strong corrosion and other media. Then convert it to 4-20mA. DC signal output

Mainly used for measurement in the following occasions:

  • Viscous medium at high temperature.
  • Easily crystallized medium.
  • Precipitated media with solid particles or suspended matter.
  • Strongly corrosive or highly toxic media.
  • It can eliminate the leakage of the pressure guiding pipe and pollute the surrounding environment. When the isolation liquid is used, the tedious work of frequently replenishing the isolation liquid due to the unstable measurement signal can be avoided.
  • Continuously and accurately measure the interface and density.
  • The remote transmission device can avoid the mixing of different instantaneous media, so that the measurement results truly reflect the actual situation of process changes.
  • Hygiene and cleaning requirements are high.
  • For example, in the production of food, beverage and pharmaceutical industries, not only the location of the transmitter in contact with the media must meet hygienic standards, but it should be easy to rinse.

You may like: Diaphragm pressure gauge

Extended Diaphragm Deal Application

Diaphragm seals are used for the protection of pressure measuring instruments in applications with difficult media. In diaphragm seal systems, the diaphragm of the diaphragm seal affects the separation of the instrument and the medium.

The pressure is transmitted to the measuring instrument via the system fill fluid which is inside the diaphragm seal system.

For the implementation of demanding customer applications, there are a wide variety of designs, materials and system fill fluids available.

Applications

  • Aggressive, highly viscous, crystallising or hot media
  • Process industry
  • Thick-walled or insulated pipelines and vessels

Read more What is a diaphragm seal?

1199EFW Extended Diaphragm Seal

The specifications of commonly used Extended Diaphragm Seals are as follows:

DN50 (2 ”) flange size specification table

FlangeACFEBNumber of bolts nBolt diameter
150LB150120954819418
300LB165127954820818
600LB165127954832818
900LB215165954845826
PN1.6/1.0165125954818418
PN2.5/4.0165125954820418
PN6.4180135954826422

DN80 (3 ”) flange size specification table

FlangeACFEBNumber of bolts nBolt diameter
150LB1901521247420418
300LB2101681247425822
600LB2101681247438822
900LB2401911247454826
PN1.6/1.02001601247420818
PN2.5/4.02001601247424818
PN6.42151701247428822

DN100 (4 ”) flange size specification table

FlangeACFEBNumber of bolts nBolt diameter
150LB2301901558924418
300LB2552001558932822
600LB2752151558945826
900LB2902351558950833
PN1.6/1.02001801558920818
PN2.5/4.02001901558924822
PN6.42152001558928826

Rosemount 1199 remote transmission diaphragm system provides the world’s most extensive product variety and specifications to meet the requirements of various measurements and applications.

There are the following types of remote transmission differential pressure / level transmitters:
1) PFW flat type remote transmission device
2) RTW thread installation type remote transmission device
3) EFW inserted barrel remote transmission device
4) RFW flange mounted remote transmission device
5) SCW hygienic remote transmission device

The 1199 remote diaphragm can be assembled to Sino-Inst differential, gauge and absolute pressure transmitters and liquid level transmitters.

Extended reading: SI-703 Flush Diaphragm Pressure Sensor

Diaphragm type level transmitter working principle

Smart differential pressure transmitters are often used to measure liquid level, flow rate, etc. Differential pressure transmitter cooperates with sealing diaphragm, capillary, etc.

The differential pressure type liquid level gauge uses the principle that when the liquid level in the container changes, the static pressure generated by the liquid column also changes accordingly, as shown in the figure.

For closed tanks. Set the bottom pressure to P. If the pressure on the liquid surface is P3 and the liquid level height is H, then:

P = P3 + Hpg (3-11)

In the formula: p is the medium density; g is the acceleration of gravity.
From the formula ((3-1 “available:
△ P = P-P3 = Hpg (3-12)

Usually the density of the measured medium is known, the pressure difference △ P is proportional to the liquid level height H. The pressure difference on the side will know the measured liquid level height.

When the container under test is open, the gas pressure is atmospheric pressure. The negative pressure chamber of the differential pressure gauge can be vented to the atmosphere. It is known that the pressure gauge can also be used to measure the liquid level at this time. If the container is closed, you need to connect the negative pressure chamber of the differential pressure gauge to the gas phase of the container.

Pressure level transmitter is good for level measurement. Most of the time, we use submersible hydrostatic level sensor for the level measurement. When you can not use the probe of hydrostatic level sensor, you can try with this pressure level transmitter. Pressure level transmitter, is one type of DP level measure instrument, with the diaphragm.

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SMT3151LT Differential pressure (DP) level transmitter a new type of differential pressure (DP) transmitter produced by advanced technology and equipment. Continuous level, flow and differential pressure measurement. Liquid level measurement, is the most common measurement process in continuous production processes, such as: petroleum and chemical industry. The liquid level measuring instrument currently widely used, is the differential pressure level transmitter.

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SMT3151DP intelligent differential pressure transmitter uses advanced microprocessor technology and digital communication technology. The basic principle of differential pressure transmitter is: divide a space with sensitive elements (multi-purpose capsule) into two chambers. Introduce pressure into the two chambers separately. The sensor produces displacement (or displacement trend) under the combined action of the two pressures. This displacement is proportional to the pressure difference (differential pressure) between the two chambers. Convert this displacement into a standard signal output that can reflect the magnitude of the differential pressure.

Comparative analysis – 7 Tank Level Measurement Sensors

You may like: differential pressure transmitter working principle|Working Principle of pressure level transmittersdifferential pressure level transmitter working principle

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SI-D100 Diaphragm Pressure Gauge

The diaphragm pressure gauge application spans from 10 mbar to 60 bar. The measuring element consists of one circular diaphragm, clamped between a pair of flanges.

The positive or negative pressure, acting on these diaphragms causes deformation of the measuring element. The magnitude of the deformation is proportional to the pressure to be measured, and it is coupled to the pointer mechanism.

Features of the diaphragm pressure gauge

SI-D100 Diaphragm pressure gauge

  • Case and wetted parts from stainless steel
  • Wide choice of special materials
  • High overload safety up to the 10-fold full scale value
  • Process connection thread or open flange
  • Scale ranges from 0 … 60bar

You may like:

Diaphragm Seal Pressure/ Differential Pressure Transmitters

Submersible Pressure Transmitter for Level and Depth Measurement

Specifications of SI-D100 Diaphragm pressure gauge

Pressure gauges compliant with EN 837-3
Display ranges
 
0…10 mbar to 0…40 bar (unfilled)
0…60 mbar to 0…60 bar (filled)
Nominal size
 
100 mm
160 mm
Mechanical designStainless steel case with bayonet ring
Connections at bottom
the enlarged channel opening
in case of PTFE lining,
optional open flange
 Stainless steel
 
EN 837-3 accuracy
 
Class 1.6
Class 2.5 (with protecting foil)
Maximum pressure load
Static load
Dynamic load
Overload
 100 % of full scale values
90 % of full scale values
Up to 5-times, max. 40bar

Connection threads and materials of SI-D100 Diaphragm pressure gauge

Type 316L pressure gauges with stainless steel connection are available with a stainless steel diaphragm (40 to 250 mbar) , or a Duratherm diaphragm (0.4 to 40 bar).

In addition, they can optionally be produced with PTFE lining.

Options of SI-D100 Diaphragm pressure gauge

  • Inlet port orifice up to Ø 10 mm
  • Hygienic connection,
    • e.g. according to DIN 11851, DN 25 to DN 50,
    • with or without lateral cleaning valve
  • Other connection flanges according to former DIN standards
  • Special installation or connection orientation
  • Special scales such as dual ranges, fine-division (with knife-edge pointer) Stationary red pointer on the dial, or with external adjustment)
  • Maximum indicating pointer, external adjustment
  • Window acryl glass or polycarbonate (only for display ranges ≥ 0…100 mbar)
  • Micro-adjustable pointer, mechanism aluminum
  • Diaphragm with protection foil:
    • PTFE (> 40 mbar, vacuum tight), sealing PTFE;
    • Fine-silver (> 160 mbar, vacuum tight), sealing FPM;
    • Tantalum (> 160 mbar, vacuum tight upon request), sealing PFTE, others upon request
  • Up to 10-times overload protection, but max. 40 bar (600 psi) for measuring flange Ø 100 mm (3.94“) max. 2.5 bar (40 psi) for measuring flange Ø 160 mm (6.3“)
  • Other filling fluid, silicone oil for temp. down to -40 °C (flange sealing PTFE)
  • Version for temperatures > 100 °C
  • Electrical accessories

More Diaphragm Pressure Gauge Technical Guide

A diaphragm pressure gauge is a tool that measures the pressure of a gas or liquid by using a flexible diaphragm. The diaphragm will move in response to changes in pressure, and this movement is then translated into a reading on a dial.

These gauges are commonly used in industries like manufacturing, oil and gas, and chemical processing to monitor and control pressure in various processes. They are also commonly used in HVAC systems to measure the pressure of air and other gases.

Diaphragm pressure gauges are relatively easy to use and maintain, and they are often chosen for their accuracy, durability, and affordability. They come in different sizes, materials, and pressure ranges, making them versatile tools that can be used in a wide range of applications.

Diaphragm pressure gauge construction

A diaphragm pressure gauge is a device that uses a diaphragm with a known pressure to measure pressure in a fluid.

It has many different uses, such as monitoring the pressure of a canister of gas, measuring atmospheric pressure. Or recording the strength of the vacuum in a vacuum pump.

The diaphragm pressure gauge consists of a circular membrane, made from sheet metal of precise dimensions, which can either be flat or corrugated.

The diaphragm is mechanically connected to the transmission mechanism, which will amplify the small deflections of the diaphragm, and transfer them to the pointer.

The animation below shows the pressure gauge working principle.

You can see the movement of the diaphragm and the functioning of the transmission mechanism.

The process pressure is applied to the lower side of the diaphragm, while the upper side is at atmospheric pressure.

The differential pressure arising across the diaphragm lifts up the diaphragm and puts the pointer in motion.

The deflection of the diaphragm is very small (+/- 1 mm), making it necessary to use a high-ratio multiplying movement, to rotate the pointer along the full length of the scale.

The actuation of such a high-ratio transmission mechanism is possible, because diaphragm deflection is able to generate large forces.

Read more What is a diaphragm seal?

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Advantages:Disadvantages:
Versatility: can measure pressure of a wide range of fluids and gasesLimited range: may not be suitable for high or low pressures
Accuracy: provide precise measurementsSensitivity to overpressure: can be damaged and affect accuracy
Cost-effective: relatively affordableSusceptibility to damage: diaphragm can be damaged by certain fluids
Durability: made of durable materials and can withstand harsh conditionsEnvironmental factors: accuracy can be affected by changes in temperature, humidity, etc.

Pressure gauges with horizontal diaphragm allow to find suitable versions for even difficult kinds of media. Such as aggressive, contaminated or viscous media.

The stainless steel bayonet ring case is designed for applications, where a rust-resistant, sealed case of high chemical resistance is required (dirty damp, or corrosive atmosphere).

  • For measuring points with increased overload;
  • With liquid-filled case suitability for high dynamic pressure loads and vibrations (model 433.50);
  • For gaseous, liquid and aggressive media, also in aggressive environments;
  • With the open connecting flange option also for contaminated and viscous media;
  • Process industry:
    • Chemical, petrochemical, power plants, mining,
    • on-/offshore, environmental technology,
    • machine building and general plant construction

There are various types of pressure instruments. In addition to pressure sensors, pressure transmitters. Pressure gauges are also commonly used.

The function of a pressure gauge is to measure the pressure of fluids and gases in various industrial, commercial, and residential applications. Pressure gauges are used to monitor and regulate the pressure of liquids and gases in tanks, pipelines, and other containers to ensure that They are operating safely and efficiently.

The pressure gauge works by measuring the force that the fluid or gas exerts on a sensing element, which is typically a flexible diaphragm or a curved tube called a Bourdon tube. The sensing element then converts this force into a mechanical or electrical signal, which is displayed on the gauge as a pressure reading.
.

In summary, the function of a pressure gauge is to provide accurate and reliable measurements of pressure in various applications to ensure the safety and efficiency of systems and equipment.

Difference between bourdon tube and diaphragm pressure gauge

The working principle of the pressure gauge is through the elastic deformation of the sensitive element in the gauge. Then the pressure change is transmitted to the pointer by the conversion mechanism of the movement in the watch. Cause the pointer to rotate to show pressure. Sensitive element may be a Bourdon tube, diaphragm, bellows.

Therefore, the essential difference between the bourdon tube and diaphragm pressure gauge is the different sensitive components for pressure measurement.

Bourdon tube pressure gauge:
The sensitive element of the Bourdon tube is an elastic C-shaped tube bent into a circle with an oval cross-sectional area. The pressure of the measuring medium acts on the inside of the wave tube. In this way, the elliptical cross-section of the Bourdon tube will tend to be circular. Due to the slight deformation of the Bourdon tube, a certain ring stress is formed. This ring stress causes the Bourdon tube to extend outward. Since the head of the elastic Bourdon tube is not fixed, it will deform slightly. The amount of deformation depends on the pressure of the measuring medium. The deformation of the Bourdon tube displays the pressure of the measured medium indirectly by the pointer through the movement.

Diaphragm pressure gauge:
The sensitive element of the Diaphragm is composed of two membranes with circular waves connected together. The pressure of the measuring medium acts on the inside of the capsule cavity. The resulting deformation can be used to indirectly measure the pressure of the medium. The pressure value is indicated by the pointer. The capsule pressure gauge is generally used to measure the pressure of the gas, and it can also measure the micro-pressure and over-pressure protection to a certain extent. When several bellows sensitive components are stacked together, a large transmission force will be generated to measure very small pressure.

Bourdon tubes have the following advantages over diaphragm elements:

  • They cover small pressure ranges from 0 to 0.6 bar up to high pressure ranges from 0 to 10,000 bar.
  • They enable accuracies up to class 0.1 of the calibration regulations.
  • They are easier to manufacture.
  • They can easily be connected or sealed with the pressurised components. Depending on the material and pressure load, they are either soldered, welded or screwed to them.

Diaphragm pressure gauges are used when a Bourdon tube pressure gauge reaches its limits.

Extended reading: Pressure indicator transmitters

Frequently
Asked
Questions

In a pressure gauge, a diaphragm is a flexible membrane that responds to changes in pressure by expanding or contracting. The movement of the diaphragm is then converted into a reading on the gauge, which displays the pressure of the fluid or gas being measured.

Diaphragms can be made from a variety of materials, such as stainless steel or synthetic materials like rubber or silicone. They are designed to be durable and withstand the pressure and conditions of the environment in which they are used.

The capsule pressure gauge is also called micro pressure gauge. It is suitable for measuring the low micro-pressure of liquid, gas or steam which has no explosion risk, no crystallization, no solidification, and corrosive effect on copper and copper alloys.
The capsule pressure gauge uses the capsule as a sensitive element for measuring small pressures. Measure the micro-pressure and negative pressure of the corrosive effect on the copper alloy, no explosion hazard gas. Widely used in boiler ventilation, gas pipeline, combustion device and other similar equipment.

In the pressure gauge, the pressure measured by the diaphragm is generally regarded as relative pressure. Generally, the relative point is selected as atmospheric pressure. The elastic deformation of the diaphragm under the pressure of the medium. Amplified by the gear transmission mechanism of the pressure gauge. The pressure gauge will show the relative value to the atmospheric pressure (either high or low).

There are several different types of pressure gauges that are commonly used in different applications:

Bourdon Tube Pressure Gauge: This type of gauge uses a curved tube that is attached to the gauge mechanism. As the pressure of the fluid or gas being measured increases, the tube straightens out, causing the gauge mechanism to move and display the pressure reading.

Diaphragm Pressure Gauge: As we discussed earlier, diaphragm pressure gauges use a flexible membrane that responds to changes in pressure by expanding or contracting. This movement is then converted into a reading on the gauge.

Differential Pressure Gauge: This type of gauge measures the difference in pressure between two points in a system. It consists of two pressure inputs and a gauge mechanism that calculates the difference between the two inputs.

Digital Pressure Gauge: This type of gauge uses electronic sensors to measure pressure and displays the reading on a digital screen.

Compound Pressure Gauge: This type of gauge can measure both positive and negative pressures. It uses two Bourdon tubes, one for positive pressure and one for negative pressure, to display the reading on the gauge.

Overall, the type of pressure gauge used will depend on the specific application and requirements. Each type of gauge has its own advantages and disadvantages, and it’s important to choose the right one for the job.

More pressure measurements and applications

Sino-Instrument offers over 50 Diaphragm pressure gauge products.

About 50% of these are Diaphragm pressure gauge, 40% are Differential Pressure Gauge, and 40% are Diaphragm Seal Pressure transmitters.

A wide variety of  Diaphragm pressure gauge options are available to you, such as free samples, paid samples. 

Sino-Instrument is a globally recognized supplier and manufacturer of Diaphragm pressure gauge, located in China.

The top supplying country is China (Mainland), which supply 100% of Diaphragm pressure gauge respectively.

Sino-Instrument sells through a mature distribution network that reaches all 50 states and 30 countries worldwide. Diaphragm pressure gauge products are most popular in Domestic Market, Southeast Asia, and Mid East. 

You can ensure product safety by selecting from certified suppliers, with ISO9001, ISO14001 certification.

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SI3151 Level TRANSMITTERS Direct Mounted Flange Type

Sino-Instrument > level transmitter > Hydrostatic for Liquids

High-performance level measurement using a differential pressure transmitter.

  1. High-reliability micro-capacitance silicon cell
  2. All welded construction with no flange ‘O’ rings
  3. Exceptional resistance to harsh environments
  4. Electronic linearisation to correct tank shape
  5. Hart® 5.2 multi-drop communication
  6. Versatile indicator with 5-digit display
  7. Field repair possible with common spare parts
  8. The built-in loop calibration facility
  9. Wide range of flange types
  10. Large installed base

Most DP type level transmitters use an ‘O’ ring seal,

which will perish within 6 to 12 months usage in a hostile process environment. 

The FCX series transmitter uses an all-welded construction with fill fluid,

that has been subjected to high vacuum for an extended period to remove entrained air. 

This provides long term reliability not found in any level transmitter of its type.

Each application is different. Please feel free to get in touch to discuss your requirements.

Data sheet:

https://www.drurylandetheatre.com/SI/SMT3151TLT Direct-mounted level (pressure) transmitter.pdf

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SMT3151 Remote Diaphragm Seal Pressure Transmitter

Remote seal pressure transmitter, with capillary and diaphragm seal, remote mount. Diaphragm seal systems protect pressure transmitters from hot, viscous, contaminated or corrosive media.

Remote Diaphragm seal pressure transmitter with capillary is used as a level transmitter. Diaphragm Seals also called chemical seals, are used in applications where pressure sensor requires isolation from the process media. These applications are corrosive, high temperature, clogged. Or must sanitary fluids to remain in the pipeline or container. The pressure of the liquid in the process does not affect the pressure sensor. Instead, it is applied to the remote seal. And through the capillary, hydraulic pressure is transmitted to the pressure sensor. Installing and filling the diaphragm seal, the impact on instrument performance will be minimized.

Sino-Inst also offers repair, refurbishment or replacement of used transmitters with remote seals.

Features of Remote Diaphragm Seal Pressure Transmitter

Protect pressure sensor

The remote transmission diaphragm can protect the transmitter diaphragm from corrosive, aggressive or extreme temperature.

Various sealing diaphragms are available

Sino-Inst can provide a suitable sealing diaphragm according to your measurement requirements. For example, remote threaded seal, flush flanged type seals, remote flange seal-RTJ gasket surface, extended flanged seal, etc.

Suitable for special environments.

Such as:
High / low temperature fluids;
Highly corrosive / high viscosity fluids;
Toxic fluids;
The fluids containing suspended solids which are deposited in the impulse piping and may cause clogging.

Specifications of Remote Diaphragm Seal Pressure Transmitter

 Measurement parameters: pressure, liquid level
 Measuring range: lower limit: -100% URL (continuously adjustable);
upper limit: to + 100% URL (continuously adjustable)
 Output: two-wire system, 4-20mADC + HART output, digital communication; output signal limit: Imin = 3.9mA, Imax = 20.5mA
 Alarm current:①Low report mode (minimum): 3.7mA
②High report mode (maximum): 21mA
③No report mode (hold): keep the effective current value before the fault
④Alarm current standard setting: high report mode
 Response time: the damping constant of the amplifier part is 0.1s; the time constant of the sensor and the remote flange is 0.2-6s, which depends on the range of the sensor, the range ratio, the length of the capillary, and the viscosity of the filling fluid The additional adjustable time constant is: 0.1-60s.
 Ambient temperature: minimum: depends on the filling liquid; maximum: 85 ℃; with liquid crystal display, fluorine rubber sealing ring is -20 ~ +65 ℃
 Storage temperature / transport temperature: minimum: depends on filling liquid; maximum: 85 ℃
 Relative humidity: 0-100%
 Anti-shock: acceleration: 50kg; duration 11ms
 Anti-vibration: 2g to 500Hz
 Process medium temperature limit: medium temperature: -20 ~ 400 ℃
 Pressure limit of transmitter body: vacuum to maximum pressure
 Rated pressure of remote flange: ANSI standard: 150psi-600psi; DIN standard: PN1.6MPa-PN10MPa
 Warm-up time: <15s
 Explosion-proof performance: NEPSI explosion-proof license: ExdⅡCT6; NEPSI intrinsically safe license: ExiaⅡCT4; allowable temperature is -40 ~ + 65 ℃
 Power and load conditions:① The power supply voltage is DC24V, R≤ (Us-12) / Imax kΩ, where Imax = 23mA
②Max power supply voltage: 42VDC
③Minimum power supply voltage: 12VDC, 15VDC (backlit LCD display)
④Digital communication load range: 250-600Ω
 Electrical connection: M20 × 1.5 cable sealing buckle, the terminal is suitable for 0.5-2.5mm2 wire
 Process connection: The remote flange meets ANSI standard or DIN standard. Can be installed directly, please refer to the dimension drawing for flange size
 Material: Measuring capsule: stainless steel 316L; diaphragm: stainless steel 316L, Hastelloy C, tantalum
 Process connection: stainless steel 316
 Filling fluid: silicone oil, high temperature silicone oil, ultra high temperature silicone oil, vegetable oil
 Pressure transmitter shell: aluminum alloy material, epoxy resin on the surface
 Shell sealing ring: NBR
 Nameplate: Stainless steel 304
 Weight:DN50 / 2 inches about 7-10kg; DN80 / 3 inches about 8-11kg; DN100 / 4 inches about 9-12kg
 Shell protection grade: IP67

Read more What is a diaphragm seal?

Types of SMT3151 Remote Diaphragm Seal System Pressure Transmitters

3151T flange type remote pressure transmitter

The selection is as follows:
3151TGP4SF00S1M4B4 0~40kPa
1199FFW A50AADL03H00

On behalf of the 3151TGP base table plus an American standard 2”150LB flange type remote transmission device, the capillary length is 3 meters.

3151T flat remote pressure transmitter

The selection is as follows:
3151TGP4SF00S1M4B4 0~40kPa
1199PFWA50AADL03H00

On behalf of the 3151TGP base table plus an American standard 2”150LB flat remote transmission device, the capillary length is 3 meters.

3151T type insert barrel remote pressure transmitter

The selection is as follows:
3151TGP4SF00S1M4B4 0~40kPa
1199EFWA50AABDL03H00

On behalf of the 3151TGP base table plus an American standard 2”150LB plug-in remote transmission device, the capillary length is 3 meters, the insertion barrel length is 100mm.

3151T threaded remote pressure transmitter

The selection is as follows:
3151TGP7SF00S1M4B4 0~1000kPa
1199RTWA1AADL03H00

On behalf of the 3151TGP base table plus a threaded connection remote transmission device, capillary length of 3 meters, user connection thread specifications 1/2NPT-14.

3151T type three clamp type remote pressure transmitter

The selection is as follows:
3151TGP5SF00S1M4B4 0~100kPa
1199SCWA1A0DL03H00

On behalf of the 3151TGP base table plus a three-clamp type remote transmission device, the capillary length is 3 meters, the user connection clamp specification is 1 1/2 inch.

3151GP/DP flange type remote pressure transmitter

The selection is as follows:
3151GP4SF22S1M4B3 0~40kPa
1199FFW A50AADL03H00

On behalf of the 3151GP base table plus an American standard 2”150LB flange type remote transmission device, the capillary length is 3 meters.

3151GP/DP flat remote pressure transmitter

The selection is as follows:
3151GP4SF22S1M4B3 0~40kPa
1199PFWA50AADL03H00

On behalf of the 3151GP base table plus an American standard 2”150LB flat remote transmission device, the capillary length is 3 meters.

3151GP/DP type insert barrel remote pressure transmitter

The selection is as follows:
3151GP4SF22S1M4B3 0~40kPabr>
1199EFWA50AABDL03H00

On behalf of the 3151GP base table plus an American standard 2”150LB plug-in remote transmission device, the capillary length is 3 meters, the insertion barrel length is 100mm.

3151GP/DP type threaded remote pressure transmitter

The selection is as follows:
3151GP7SF22S1M4B3 0~1000kPa
1199RTWA1AADL03H00

On behalf of the 3151GP base table plus a threaded connection remote transmission device, capillary length of 3 meters, user connection thread specifications 1/2NPT-14 specific size,

3151GP/DP type three clamp type remote pressure transmitter

The selection is as follows:
3151TGP5SF22S1M4B3 0~100kPa
1199SCWA1A0DL03H00

On behalf of the 3151GP base table plus a three-clamp type remote transmission device, the capillary length is 3 meters, the user connection clamp specification is 1 1/2 inch.

Diaphragm Seal System

Remote Diaphragm seal pressure transmitter, is the capillary type pressure transmitter. This type pressure transmitter, assembling diaphragm seals to field transmitters for the purpose of measuring pressure, differential pressure, level, and flow.

Diaphragm seals are used to prevent process medium from entering into the pressure-sensing assembly of the Differential pressure, Gauge pressure, or Absolute pressure transmitter.

Applications which is suitable for diaphragm seal system

  • For measuring the liquid level, density, flow and pressure of ;
  • high/low-temperature fluids;
  • highly corrosive/high viscosity fluids ;
  • the fluids which may cause clogging of impulse piping in the low temperature ;
  • toxic fluids;
  • the fluids containing suspended solids, which are deposited in the impulse piping and may cause clogging.
How do diaphragm seals work?

You may like: Diaphragm pressure gauge

How do diaphragm seals work?

Basically, diaphragm seals are used in all pressure measurement processes to avoid direct contact between the measuring instrument and the medium during this process. In addition, if the measuring point cannot be installed or read because the measuring point is located in a hard-to-reach location, a diaphragm seal can also be used. In both cases, the applied pressure is transferred to the measuring instrument through the system fill fluid in the diaphragm seal housing.
The diaphragm of the seal can be made of different materials, such as stainless steel, Hastelloy, Monel or tantalum. In addition, coatings with ECTFE, PFA or gold can also be used.

We can provide the best diaphragm seal design, materials, system fill fluid and accessories for each application. The combined configuration of the pressure measuring instrument and the diaphragm seal is mainly determined by the special application conditions of the diaphragm sealing system.

How does a diaphragm pressure sensor work?

When the diaphragm seal pressure transmitter is working, the high and low pressure side isolation diaphragms and the filling liquid transfer the process pressure to the center filling liquid. The filling fluid in the center transmits the pressure to the sensing diaphragm in the center of the δ-chamber sensor. The sensing diaphragm is a tensioned elastic element, and its displacement changes with the differential pressure. For GP gauge pressure transmitters, the atmospheric pressure is applied to the low-pressure side of the sensing diaphragm. AP absolute pressure transmitter, the low pressure side always maintains a reference pressure. The maximum displacement of the sensing diaphragm is 0.004 inches (0.10 mm). The displacement is proportional to the pressure. The two capacitance fixed plates of the measuring diaphragm are linearly converted into a 2-wire current, voltage or digital HART output signal of 4-20mADC by the amplifying circuit.

What is a diaphragm seal?

Diaphragm seals, also known as chemical seals or remote seals, are used for pressure measurements when the process medium should not come into contact with the pressurised parts of the measuring instrument.

A diaphragm seal has two primary tasks:

  1. Separation of the measuring instrument from the process medium
  2. Transfer of the pressure to the measuring instrument

Extended reading: SI-703 Flush Diaphragm Pressure Sensor

What is remote seal?

The remote seal is used to prevent the medium in the pipeline from directly entering the pressure sensor assembly in the pressure transmitter. It is connected to the transmitter by a capillary filled with fluid. As a result, they’re often used in refining, petrochemical, and chemical plants.

Applicaitons of diaphragm seal

Typical applications where a diaphragm seal provides a cost-effective solution, to protecting the pressure instrument are:

  • In applications where the process fluid is corrosive;
  • In applications where the process fluid has a high viscosity,
    is comprised of slurries, sludge or other material that can actually coat,
    or damage a traditional pressure measuring device;
  • In applications where the process fluid can freeze or polymerize,
    thus causing a condition that might lead to the instrument becoming immobilized,
    or incapable of transmitting an accurate pressure measurement or signal.

The process side of the seal is isolated by a flexible diaphragm. The internal space between this diaphragm and pressure measuring sensor is filled with a system fill fluid. The pressure is transmitted from the measured medium, by the elastic diaphragm into the fluid. And from there to the measuring element, i.e. to the pressure measuring instrument or the transmitter.

Often, between the diaphragm seal and pressure measuring instrument, a capillary is connected. Capillary can eliminate or to minimize temperature effects from the hot fluid to the measuring instrument.

A Remote seal is mounted to the process by threaded, flanged, in-line, sanitary, or other connections. Usually, the fittings consist of T-pieces which are integrated into a pipeline, or of welding sockets which are welded to a pipeline, the process reactor or a tank.

This diaphragm seal type offers the advantage, that the “contact surface” between pressure medium and the diaphragm is relatively large. Thus ensuring accurate pressure measurement, especially for very low pressures (< 600 mbar).

Although standard remote seal bodies and diaphragms, are made of stainless steel, a variety of materials, from carbon steel to Hastelloy® C-276, are available to meet the demand of most applications.

A remote seal from Sino-Instrument can operate in pressure applications from 10″ Hg to 20,000 psi, and media temperatures between -130°F and 752°F. We can try to Learn more about the functionality, areas of application and advantages of a diaphragm seal in the following WIKA video.

Extended reading: Flat Pressure Sensor for High Viscosity Fluids

Diaphragm type pressure transmitter

https://www.drurylandetheatre.com/diaphragm-sealed-differential-pressure-transmitters-for-sale/

Data sheet of SMT3151 Diaphragm Seal Pressure transmitters

Diaphragm seal pressure transmitter installation

  1. The remote pressure transmitter without capillary can be directly installed through the remote flange. The position deviation will produce a correctable zero offset
  2. The electronic watch case can rotate 360 degrees at the maximum. The positioning screw can fix it at any position.
  3. Single-crystal silicon remote flange is connected with the matching flange conforming to ANSI / DIN standard. The matching flange should be equipped with soft gasket and fixed bolts and nuts. The user can choose to install bolts and nuts.
  4. For the remote transmission pressure transmitter with capillary, if the remote transmission sealing device is lower than the transmitter body, the maximum height drop between the remote transmission sealing device and the transmitter body should be less than 5m. When the working pressure is lower than 100kPa absolute pressure, the transmitter body must be lower than the remote transmission sealing device.
  5. The minimum bending radius of the capillary is 75mm, winding is strictly prohibited

Q&A

Parameters that determine the design of a remote seal transmitter

Location of the transmitter (indoor versus outdoor).
Temperatures (process and ambient).
Exposure to vacuum.
Pressure (operating and maximum).
Length of capillary.
Type of seal desired.
Process connection, material of construction and similar considerations.
Installation requirements.
Measurement span.

When are threaded connections used with diaphragm seals?

The combinations of diaphragm seals with threaded connection can be used for processes with extreme temperatures and with aggressive, adhesive, corrosive, environmentally hazardous or toxic media.

Why are there different system fill fluids with diaphragm seals?

In selecting the system fill fluid for diaphragm seals, factors such as compatibility (physiologically harmless) and also temperature and pressure conditions at the measurement location are of crucial importance. Depending on the system fill fluid, the appropriate minimum and maximum operating temperature range must be observed.

How are the diaphragm seals connected?

The diaphragm seals are available with female or male thread in their basic design. Due to the wide variety of available process connections they can be mounted to many different connections without any problems. Generally these connections are T-pieces which are integrated into a pipeline or welded to a pipeline by means of a welding socket.

Sino-Instrument offers SMT3151 Diaphragm Seal Pressure transmitter. Work the same as Wika diaphragm seal pressure transmitter; diaphragm seal pressure transmitter Rosemount; Yokogawa diaphragm seal pressure transmitter.

Sino-Instrument are diaphragm seal pressure transmitters manufacturer. We can offer you automated instruments from China, With best price.

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Diaphragm Seal Pressure Level Transmitter

SMT3151TLT Pressure Level Transmitter is an economical flange direct-mounted pressure transmitter. An isolation diaphragm box is added as the measuring liquid contact part. One port is connected to the process tank (or pipeline) by flange (or other connection method).
Mainly used to measure high-temperature, easy to solidify or crystallize, containing suspended solids, too viscous, corrosive or other media that need to maintain sanitary conditions and cannot be contaminated.

Sino-Inst offers a variety of Diaphragm Seal Pressure Transmitters for industrial pressure measurement. If you have any questions, please contact our sales engineers.

Features of Pressure Level Transmitter

  1. Diffusion silicon isolation sensor
  2. Flange installation
  3. Large size diaphragm, fully welded and sealed, long-term reliable and durable
  4. Aluminum alloy junction box with strong seal and good outdoor installation
  5. Used for pressure measurement of gas, liquid and steam
  6. Anti-corrosion metal diaphragm optional
  7. With LCD display optional
  8. Especially suitable for high temperature or viscous liquid
  9. The flange size is customized according to customer requirements. And the installation is flexible and diverse

Read more about Steam pressure transmitter-Pressure measure on steam pipeline 

Specifications of Pressure Level Transmitter

ModelTransmitter type
SMT-3151TLTFlange level transmitter
CodeScale range
2
3
4
5
0-20~100kPa(0-2000~10000mmH2O)
0-70~350kPa(0-7~35mH2O)
0-200~1000kPa(0-20~100mH2O)
0-700~3500kPa(0-70~350mH2O)
CodeOutput form
ELinear output 4-20mAdc
SFLinear output 4-20mAdc+HART signal,Full function buttons on site
FMODBUS-485 signal
CodeFlange standard (high pressure side flange)
AANSI American Standard (HG20615)
DDIN European standard(HG20592)
CodeProcess connection size
ANSI American Standard (HG20615)DIN European standard(HG20592)
251″DN25
401.5″DN40
502″DN50
803″DN80
004″DN100
CodeProcess connection withstand voltage rating
ANSI American Standard (HG20615)DIN European standard(HG20592)
A150LBPN16/25
B300LBPN40
C600LBPN64
D900LBPN100
CodeMeasuring diaphragm
A316 Stainless steel
BHastelloy C
CMonel
DTantalum
ETitanium
FSpecial requirements
CodeInsert barrel lengthInsert barrel material
A0 mmNone
B50 mm316L Stainless steel
C150 mm316L Stainless steel
D200 mm316L Stainless steel
CodeFilling liquid
DOrdinary silicone oil  (-40~104℃)
FHigh temperature silicone oil   (-40~304℃)
SInert liquid  (-40~204℃)
CodeShell materialConduit inlet dimensions
ALow copper aluminum alloy polyurethane coatingM20×1.5
BLow copper aluminum alloy polyurethane coating1/2-14 NPT
CStainless steelM20×1.5
DStainless steel1/2-14 NPT
CodeOptional parts
M10~100%  Linear indicator
M4LCD Multi-function digital display
DaFlameproof  ExdIIBT5Gb;(explosion-proof certificate No. : CE16.1163)
FaIntrinsically safe ExiaIICT4 / T5 / T6Ga;(explosion-proof certificate No. : CE15.2354X)
CXWith corresponding 316 flushing ring

You may like: Explosion Proof Pressure Transmitter for Hazardous locations

Applications for Pressure Level Transmitters

The application which is suitable for diaphragm seal system… For measuring the liquid level, density, flow, and pressure of :

  • High/low temperature fluids
  • Highly corrosive/high viscosity fluids
  • The fluids which may cause clogging of impulse piping in the low temperature
  • Toxic fluids
  • The fluids containing suspended solids which are deposited in the impulse piping and may cause clogging.\

Extended reading: Featured Diaphragm Seal Pressure Transmitters

Diaphragm flange material selection

The biggest advantage of the Diaphragm Seal Pressure Level Transmitter is that different diaphragm materials can be selected. According to different corrosion, media to achieve the best corrosion resistance. The commonly used diaphragm materials are SUS316L stainless steel. Tantalum, Hastelloy, Monel, Pure titanium, F4, etc. 

When choosing a diaphragm pressure transmitter, in addition to the correct choice of structure and range, the more important thing is to choose the material. The so-called reasonable is to consider its corrosion resistance, but also to consider the economy. For example, the corrosion resistance of the tantalum diaphragm and Hastelloy is excellent, but it is expensive. Only used in environments with high corrosivity and other cheap materials are not suitable.

The following table introduces several common corrosion-resistant materials that can be selected for corrosion media. For your reference.

Corrosive mediumTin bronze (QSn6.5-0.4)SUS316Pure tantalum (Ta)Monel (Ni70Cu30)Hastelloy (HC)Polytetrafluoroethylene (F4)
Sulfuric acid (H2SO4)VVVV
Nitric acid (HNO3)VVV
Hydrochloric acid (HCI)VV
Phosphoric acid (H3PO4)VVVVV
Acetic acid (CH3COOH)VVVV
Caustic soda (NaOH)V
Soda ash (Na2CO3)VV
Baking soda (NaHCO3)VV
Chlorine (CI)Dry: VDry: VDry: VVV
Wet: ╳Wet: ╳Wet: ╳
Bromine (Br2)Dry: △Dry: ╳Dry: ○V
Wet: ╳Wet: △Wet: ╳
Ammonia (NH3)VV
Seawater (30% NaCI)VVV
Explanation of symbols: ○ ——best; △ ——conditional use; V——can be used;

Extended reading: Common Pressure Sensor Applications

What is diaphragm seal pressure transmitter?

The diaphragm seal pressure transmitter is the flange type pressure transmitter. This type of pressure transmitter, assembling diaphragm seals to field transmitters for the purpose of measuring pressure, differential pressure, level, and flow.

What is a diaphragm seal?

Diaphragm Seals, also known as Chemical Seals or Gauge Isolators, are used to isolate pressure instrumentation, like pressure gauges, pressure transmitters, pressure switches, level transmitters, and more from process media that is hot, corrosive, clogging, or otherwise damaging to the pressure instrument.

A diaphragm seal has two primary tasks:

  1. Separation of the measuring instrument from the process medium
  2. Transfer of the pressure to the measuring instrument

You may like: Diaphragm pressure gauge

What is remote seal?

The remote seal is used to prevent the medium in the pipeline from directly entering the pressure sensor assembly in the pressure transmitter. It is connected to the transmitter by a capillary filled with fluid. As a result, they’re often used in refining, petrochemical, and chemical plants.

Extended reading: SI-703 Flush Diaphragm Pressure Sensor

More Pressure Measurement Solutions

FAQ

A pressure level transmitter is a device that works on the principle that static pressure is proportional to liquid level height. It is essentially a device that combines the functions of a pressure sensor and a level gauge.

The transmitter uses an advanced isolated diffused silicon sensitive element or a ceramic capacitor pressure sensitive sensor. The measured static pressure of the liquid is converted into an electrical signal.

This process is temperature compensated and linearly corrected, and the final output is a standard electrical signal, common forms are 4~20mA or 1~5VDC, etc.

Extended reading: Flat Pressure Sensor for High Viscosity Fluids

The pressure gauge is an instrument that uses elastic elements as sensitive elements to measure and indicate pressure higher than the ambient pressure. It is used in almost all industrial processes and scientific research fields.

Pressure transmitter is a device that converts pressure into pneumatic or electric signals for control and remote transmission.

The differences between pressure transmitter and pressure gauge are:

  1. The accuracy of the standard instrument required for pressure transmitter calibration is much higher than the accuracy of the standard instrument required for pressure gauge.
  2. The pressure gauge only needs to calibrate a pair of input and output relationships. The pressure transmitter may need to calibrate the relationship between input and communication data.
  3. Pressure gauge calibration must have corresponding metrological qualifications. Pressure transmitters are generally not required except for production and new construction.
  4. The pressure gauge has poor accuracy and no output. It cannot be operated with a hand operator. Generally, 5 points are calibrated. The back and forth difference is different. The intelligent pressure transmitter generally only needs to calibrate the zero point and full scale.
  5. The output of the pressure gauge is a scale indication, and its own display capability. The pressure transmitter is a current output and must be connected to an ammeter display of the corresponding accuracy level.

Extended reading: extrusion melt pressure transducer

A diaphragm seal system consists of a pressure instrument, a fill liquid, and a diaphragm seal, either direct-mount or capillary.

Diaphragm seals are used to seal and protect instruments from process media. The flexibility of the seal lies in the fact that the diaphragm securely seals the contents and penetrates the instrument to accurately measure pressure.

Diaphragm seals are often used in conjunction with pressure transmitters. This combination can be used in extremely harsh environmental conditions.

The fact that they can isolate instruments from any kind of toxic and reactive chemicals makes them particularly useful devices.

Diaphragm-sealed pressure transmitters are used when the medium is corrosive or will corrode the internal parts of the transmitter (for example, ammonia will corrode the copper in the transmitter).

Extended reading: High accuracy pressure transducers

Sino-Inst is a Pressure Level Transmitters manufacturer in China.

We offer all types of Pressure Level Transmitters. Like Direct Mounted, flange-mounted, single flange, double flange, Remote Diaphragm Seals, High Static, Digital Remote.

Most of our Pressure Level Transmitters are used in oil, liquids, DP transmitter, flow measurement, level measurement (like the ultrasonic level measurement), density, and other process variables.

You can ensure product safety by selecting from certified suppliers, with ISO9001, ISO14001 certification. We will share more about instrument calibration, like the flow transmitter calibration.

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Flange Mounted Differential Pressure Transmitter

Flange Mounted Differential Pressure Transmitter can be directly installed on the pipe or tank. Based on an ordinary pressure/differential pressure transmitter, a Flush flange or extended flange is added. It can be used for differential pressure measurement and liquid level measurement.

Mainly used to measure high temperature, easy to solidify or crystallize, containing suspended solids, too viscous, corrosive or other media that need to maintain sanitary conditions and cannot be contaminated.

Sino-Inst offers a variety of flange-mounted DP transmitters for industrial pressure measurement. If you have any questions, please contact our sales engineers.

Sino-Inst Flange Mounted Differential Pressure Transmitter uses advanced microprocessing technology and digital communication technology. It outputs a 4 to 20 mA DC signal corresponding to the measured differential pressure. It can also be configured with the HART protocol.

SMT3151LT Flange Mounted Differential Pressure Transmitter can replace EJA210E. It is a functional replacement for Rosemount 3051 and Yokogawa EJA.

Extended reading: How to calibrate HART pressure transmitters

Flange Mounted Differential Pressure Transmitter Features:

  • Used to measure the differential pressure of corrosive and non-corrosive gases, steam and liquids;
  • Using a stainless steel diaphragm;
  • Applicable to various hazardous places;
  • Output linear DC current proportional to the differential pressure value;
  • Provide various isolation diaphragms to meet special applications, such as liquid level measurement, corrosive media;
  • High measurement accuracy, 0.1%FS, 0.5%FS;
  • Extensible measurement range;
  • Aluminum and stainless steel housing;
  • With intrinsically safe explosion-proof and isolated explosion-proof capabilities. Can be used in various hazardous places.

Extended reading: Smart Differential Pressure Transmitter

Specification of Flange Mounted Differential Pressure Transmitter

ModelTransmitter type
SMT3151LTFlange liquid level transmitter
CodeScale range
40-4.0~40kPa(0-400~4000mmH2O)
50-20~200kPa(0-2~20mH2O)
60-70~700kPa(0-7~70mH2O)
70-210~2100kPa(0-21~mH2O)
CodeOutput form
ELinear output 4-20mAdc
SFLinear output 4-20mAdc +HART signal
FMODBUS-485 signal
CodeFlange standard (high pressure side flange)
AANSI American Standard (HG20615)
DDIN European Standard (HG20592)
CodeProcess connection size
ANSI American Standard (HG20615)DIN European Standard (HG20592)
251”DN25
401.5”DN40
502”DN50
803”DN80
04”DN100
CodeProcess connection pressure rating
ANSI American Standard (HG20615)DIN European Standard (HG20592)
A150LBPN16/25
B300LBPN40
C600LBPN64
D900LBPN100
CodeHigh pressure side diaphragm
A316 stainless steel
BHastelloy C
CMonel
DTantalum
ETitanium
FSpecial Requirements
CodeHigh pressure side insert tube lengthHigh pressure side insert cylinder material
A0 mmNone
B50 mm316L Stainless steel
C150 mm316L Stainless steel
D200 mm316L Stainless steel
CodeHigh pressure side filling fluid
DGeneral silicone oil  (-40~104℃)
FHigh temperature silicone oil   (-40~304℃)
SInert liquid  (-40~204℃)
Low pressure side structural materialFlange (joint)Exhaust/drain valveIsolation diaphragmSensor filling fluid
22316 Stainless steel316 Stainless steel316 Stainless steelSilicone oil
23316 Stainless steel316 Stainless steelHastelloy CSilicone oil
24316 Stainless steel316 Stainless steelMonelSilicone oil
25316 Stainless steel316 Stainless steelTantalumSilicone oil
33Hastelloy CHastelloy CHastelloy C Silicone oil
35Hastelloy CHastelloy CTantalum Silicone oil
44MonelMonelMonel Silicone oil
S2A remote transmission device (with a remote transmission device on the low-voltage side)
CodeShell materialConduit inlet dimensions
ALow copper aluminum alloy polyurethane coatingM20×1.5
BLow copper aluminum alloy polyurethane coating1/2-14 NPT
CStainless steelM20×1.5
DStainless steel1/2-14 NPT
CodeOptional parts
M10~100%  Linear indicator head
M4LCD multi – power digital display head
D1Side discharge valve at the top (only for the low pressure side of the low pressure side without remote transmission)
D2Side discharge valve at the top (only for the low pressure side of the low pressure side without remote transmission)
DaFlameproof  ExdIIBT5Gb;(explosion-proof certificate no. : CE16.1163)
FaIntrinsically safe ExiaIICT4 / T5 / T6Ga;(explosion-proof certificate no. : CE15.2354X)
CXWith corresponding 316 flushing ring

Extended Reading:

Applications

The single-flange pressure/level transmitter can accurately measure the liquid level and density of various containers. There are two types of flat flange and plug-in flange. It is suitable for high-viscosity medium or suspended liquid measurement.

  1. Viscous medium at high temperature;
  2. Easily crystallized medium;
  3. Precipitation medium with solid particles or suspended matter;
  4. Strongly corrosive or highly toxic medium;
  5. It can eliminate the leakage of the pressure guiding pipe and pollute the surrounding environment. It can avoid the instability of the measurement signal when the isolation liquid is used. The tedious work of frequently supplementing the isolation liquid is required;
  6. Continuously and accurately measure the interface and density;
  7. The remote transmission device can avoid the mixing of different instantaneous media so that the measurement results truly reflect the actual situation of process changes;
  8. Places with high sanitation requirements;
  9. Such as in the production of food, beverage, and pharmaceutical industries. Not only the transmitter contacting the media parts meet hygienic standards, but also should be easy to wash. To prevent cross-contamination of different batches of media.

Pressure level transmitter is good for level measurement. Most of the time, we use submersible hydrostatic level sensor for the level measurement. When you can not use the probe of hydrostatic level sensor, you can try with this pressure level transmitter. Pressure level transmitter, is one type of DP level measure instrument, with the diaphragm.

More

SMT3151LT Differential pressure (DP) level transmitter a new type of differential pressure (DP) transmitter produced by advanced technology and equipment. Continuous level, flow and differential pressure measurement. Liquid level measurement, is the most common measurement process in continuous production processes, such as: petroleum and chemical industry. The liquid level measuring instrument currently widely used, is the differential pressure level transmitter.

More

Flange Mounted Differential Pressure Transmitter Working principle

1. Headcover; 2. Head; 3. Metal bulkhead; 4. Shell; 5. Nameplate label; 6. Explosion-proof joint; 7. Terminal block; 8. Head cover; 9. Drain valve; 10. Bolt; 11. Clamp; 12. Sensor seal; 13. Sensor; 14. Nut; 15. Welded pipe joint assembly

The Flange Mounted Differential Pressure Transmitter is directly mounted on the reserved flange at the bottom of the pipeline or container. It contacts the liquid through the isolation diaphragm.

When the diaphragm is pressurized, it will produce a slight deformation. The displacement of the diaphragm will move with the change of the differential pressure. This change is accurately converted into a 4-20mA DC two-wire current, voltage or digital HART output signal by the amplifier circuit to achieve pressure measurement and transmission.

You may like: differential pressure transmitter working principle|Working Principle of pressure level transmittersdifferential pressure level transmitter working principle

Single flange. VS. Double flanges differential pressure level transmitter

  1. In principle: all are differential pressure transmitters + flange guide pressure;
  2. In terms of structure: the single flange liquid zd position transmitter has only one flange diaphragm box connected to the high pressure side, and the low pressure side to the atmosphere. The double flange liquid level transmitter is high and low pressure side through oil-filled capillary It is connected with two flanged membrane return boxes. There is also a capillary. The single flange transmitter is installed below, and a capillary is drawn from the low pressure side of the single flange transmitter to the upper flange membrane box.
  3. In terms of engineering applications: all can only measure the liquid level of fixed density. The single-flange transmitter can only be used for the liquid level of atmospheric equipment that can be imagined with the atmosphere. The double-flange transmitter can be suitable. Answer: Use closed equipment kettle to measure liquid level;
  4. From the economical point of view, the double flange is definitely more expensive than the single flange. After all, there is one more flange capsule and capillary.

How to choose flange type level transmitter?

Flange-level transmitters often require special environmental processing during production. Requires small range and high accuracy. Flange-level transmitters are also required to withstand high temperatures, corrosion resistance, and high overload withstand capability. Therefore, the scope of application must be clearly defined when selecting the flange type liquid level transmitter.

When choosing a flange-type liquid level transmitter, the following factors are mainly considered:

  1. The measurement object, such as the physical and chemical properties of the measured medium. And working pressure and temperature, installation conditions, speed of liquid level change, etc .;
  2. Measurement and control requirements. Such as measurement range, measurement accuracy, and display method. On-site instructions, long-distance instructions, interface with computer, safety and anti-corrosion. Reliability and construction convenience.

When selecting a double-flange differential pressure transmitter, a very important factor must be paid attention to is the differential pressure level transmitter. It is installed at the bottom of the liquid container. The height of the liquid level is reflected by the gauge pressure signal. In the control process of liquid level measurement in the pharmaceutical and chemical industries. The container holding the liquid is often under pressure. At this time, the conventional static pressure liquid level transmitter cannot meet the measurement requirements. Due to improvements in the sensor circuit and structure. Improve the practical value of differential pressure liquid level measurement technology in the pharmaceutical and food industries.

Piezoresistive Differential Pressure Transmitter
Piezoresistive Differential Pressure Transmitter utilizes the piezoresistive effect of semiconductor silicon materials. Realize accurate measurement of differential pressure.
Smart Differential Pressure Transmitter
Smart Differential Pressure Transmitter measures industrial differential pressure. Can Works with diaphragm seals, capillary, HART. Outputs standard signals (such as 4 ~ 20mA, 0 ~ 5V).
Diaphragm Seal Pressure Transmitter
When the process medium should not come into contact with the pressured parts of the measuring instrument. Diaphragm sealed pressure transmitters are used for pressure measurement.
High-Temperature Pressure Transmitter
High-temperature pressure transmitters with a 4-20mA output.
which has a temperature capability of over 850 °C and is not pyroelectric.

More Pressure and Level Measurement Solutions

Sino-Inst is one of the most excellent DP transmitters, pressure transmitters, and level transmitters suppliers. Sino-Inst can offer you a complete solution for pressure transmitters.

Sino-Inst can offer you with Flange Mounted Differential Pressure Transmitter. Our transmitters can work for you just like EJA210E.

Our Flange Mounted Differential Pressure Transmitters are widely exported to various countries. Including USA, UK, Argentina, Singapore, etc. If you need to purchase Flange Mounted Differential Pressure Transmitter, or have related technical questions, please feel free to contact our sales engineers!

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DP Level Transmitter-Differential Pressure Tank Level Measurement

DP Level Transmitter uses pressure readings and the specific gravity of the medium to calculate the liquid level. Differential pressure level measurement is a common measurement technology. It can be used for closed-tank and open-tank level measurements.

The DP Level Transmitter measurement system includes differential pressure transmitters, flanges, seal diaphragms, capillaries, wet legs/dry legs, and DP transmitters.

Sino-Inst offers a variety of DP Level Transmitters for industrial pressure measurement. Connection with diaphragm seals. If you have any questions, please contact our sales engineers.

Featured DP Level Transmitters

There are 5 types of remote transmission devices for remote differential pressure transmitters:

  1. Flat type
  2. Thread mounting type
  3. Flange mounting type
  4. Extended Diaphragm Seal
  5. Wet legs/Dry legs

Specifications of DP level transmitter

Measuring mediumLiquids, gases, and steamPressure range0-0.1kpa-40mpa
Signal output4-20mA, superimposed Hart protocol, RS485Plywood materialAll 316L stainless steel
Supply voltage12-30VDCPrecision± 0.2% FS, ± 0.1% FS, ± 0.075% FS (customizable)
Diaphragm material316L, customizable Ha C, tantalum, Monel alloyTemperature compensation-10 ~ + 70 ℃
Long-term stability (1 year)≤ ± 0.25% FSOperating temperature-20 ~ + 100 ℃
Overload pressure200% FSZero rangeExternal continuously adjustable
Destruction pressure300% FSPower effectLess than 0.005% / V of the output range
Weight3.9KG (standard type)Protection levelIP65
Volume uptakeLess than 0.16cm3Load impactIf the power supply is stable, the load has no effect

Applications of DP level transmitters

The differential pressure liquid level transmitter can prevent the measured medium from directly contacting the sensor diaphragm of the transmitter. It is suitable for the following situations:

  1.  When the measured medium has a corrosive effect on the transmitter connector and sensitive components;
  2. When the high temperature measured medium needs to be isolated from the transmitter;
  3. When there are solid suspended solids or high viscosity in the measured medium, it is easy to block the transmitter connector and the pressure chamber;
  4. When the measured medium is easily cured or crystallized by the pressure tube;
  5. When changing the measured medium needs to be rinsed and not to be mixed;
  6. Hygienic conditions must be maintained to prevent pollution. .
  7. Changing the measured medium requires strict purification of the measuring head
  8. Suspended liquid or high viscosity medium
  9. Measurement of sealed pressure vessel.

Read more What is a diaphragm seal?

Differential pressure type level transmitter working principle

The differential pressure level transmitter is an instrument that uses the pressure generated by the liquid column to measure the height of the liquid level. When the liquid level changes, the pressure received by the diaphragm at the high-pressure side flange will change accordingly. The differential pressure value calculated by the transmitter will also change accordingly. There is a linear relationship between them.

Normally, the high-pressure side (H side) and the low-pressure side (L side) cannot be installed reversely. Generally, the H side is installed at the lower part of the equipment, and the L side is installed at the higher part of the equipment. Before installation, the flange surface of the equipment should be cleaned and the gasket should not be placed off-center to prevent the diaphragm from being punctured or deformed, causing distortion of the transmitter.

SMT 3151 Differential Pressure Level Measurement

Differential pressure transmitter level measurement calculation

When using a Differential pressure (DP) level transmitter to measure the liquid level as shown in the figure below.

The measured liquid density in the figure is ρ.
The working medium density in the capillary of the double flange differential pressure transmitter is ρ0.
The measuring range of the measured liquid level is H.
The center distance of the sampling tube of the measured liquid level is h.

It can be seen from the figure that the maximum measurement range of the liquid level △ P = P + — P- = H × ρ × g – h × ρ0 × g.

It can be seen from the formula that the dual-flange differential pressure transmitter should perform negative migration. The migration amount S is h × ρ0 × g. And the installation position of the double flange differential pressure transmitter has no effect on the migration amount and the measurement result.

The dual-flange differential pressure transmitter requires negative migration.

When the measured liquid level is 0, the pressure difference between the positive and negative measurement chambers of the remote differential pressure transmitter is the largest. The output current of the double flange differential pressure transmitter is 4mA.

As the measured liquid level rises, the pressure difference between the positive and negative measurement chambers of the transmitter gradually decreases.

When the measured liquid level rises to the highest Hmax. The pressure difference between the positive and negative measurement chambers of the transmitter is the smallest. The output current of the double flange differential pressure transmitter is 20mA.

Read more about: Differential Pressure Transmitter Installation Guide

DP level transmitter calibration

The differential pressure liquid level transmitter has been calibrated in the range, accuracy, linearity and other parameters according to customer requirements at the factory. And mark the range, accuracy, etc. on the nameplate of the differential pressure liquid level transmitter. As long as the density and other parameters of the measured medium meet the requirements of the nameplate, generally no adjustment is required.

If the customer needs to adjust the range or zero position, please adjust according to the following methods. Assuming that the range of the differential pressure liquid level transmitter is 0 ~ 10 meters:

  1. Unscrew the protective cover of the differential pressure liquid level transmitter. It can be adjusted by connecting an external standard 24VDC power supply and ammeter (requires accuracy of 0.2% or above).
  2. When there is no liquid in the differential pressure liquid level transmitter. Adjust the zero potentiometers. Make it output a current of 4mA.
  3. Pressurize the differential pressure liquid level transmitter to full scale (10 meters). Adjust the full-scale resistor. Make it output a current of 20mA.
  4. Repeat the above steps two or three times until the signal is normal.
  5. Please input 25%, 50%, and 75% signals to check the error of the differential pressure liquid level transmitter.
  6. For non-aqueous media. Differential pressure level transmitters are calibrated with water. It should be converted according to the pressure generated by the actual density of the medium. For example, when the medium density is 1.3, the 1.3m water level should be used to calibrate the 1m range.
  7. After adjustment, tighten the protective cover.
  8. The verification cycle of the differential pressure liquid level transmitter is once a year.
  9. HART intelligent differential pressure liquid level transmitter of Sino-Inst instrument can be selected. It is convenient to adjust the range of the differential pressure liquid level transmitter.

You may like: pressure level transmitter

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More Pressure and Level Measurement Solutions

Sino-Inst (drurylandetheatre.com) offers over 20 DP transmitters for liquid level, pressure, flow, and density measurement. Differential pressure (DP) level transmitters are suitable for measuring water and other liquid level.

We are a differential pressure level transmitter supplier, located in China. Our products are widely exported to the United States, Australia, Singapore, Indonesia, etc. You can ensure product safety by selecting from our products, including IOS9000, and… certification.

If you need to purchase DP Level Transmitters or have related technical questions, please feel free to contact our sales engineers!

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