Professional Diaphragm Pressure Gauge Manufacturer in China

BCST Diaphragm pressure gauges is mainly  used to measure the pressure of high-viscosity or crystallising media

  • Full stainless steel for Case and wetted parts
  • Wide choice of special materials for diaphragm
  • High overload range safety up to the 10-fold full scale
  • Process connection thread or open flange
  • Scale ranges from vacuum to 60MPa
  • PTFE liner available for corrosive medium
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Your Reliable Diaphragm Pressure Gauge Supplier from China

BCST has 20 years of experience in diaphragm pressure gauge manufacturing. There are two process connections for the BCST diaphragm pressure gauge. One is thread connection, such as NPT, BSP, G, etc.., another is flange connection, include ANSI, JIS, DIN, etc.

BCST diaphragm pressure gauge features high accuracy, and the standard accuracy is 1.6%. In addition, the overpressure safety is  500 % of full-scale value, and the max working temperature is 100 C. Therefore, they have a wide application in various industries, such as petrochemical mechanical engineering, power stations, plant construction, etc.

BCST  Diaphragm Pressure Gauge meets customers’ requirements of both environmental conditions and flows conditions (corrosive media) based on its significant corrosion-proof properties. Clients can choose suitable diaphragm pressure gauges combined with an appropriate separator according to environmental conditions. They can also choose the material of diaphragm and housing compatible with corrosive media.

If you have any inquiries about diaphragm pressure gauges, welcome to send us an inquiry.

Full package of Diaphragm Pressure Gauge Solution

BCST diaphragm pressure gauge is made of a circular diaphragm and bourdon tube pressure gauge, the diaphragm of the pressure gauge is made from sheet metal of precise dimensions, it can be Teflon liner with 316SS, stainless steel, tantalum, or HC material, they are flat or corrugated.

The membrane of the diaphragm pressure gauge is mechanically associated with the spring tube transmission apparatus, the apparatus will catch up the slight deflections of the diaphragm and transfer the different pressure to the display pointer.

Video-diaphragm pressure gauge

Hot Sales Diaphragm Pressure Gauge

Bottom Connection Diaphragm pressure gauge
Bottom Connection Diaphragm Pressure Gauge
Sanitary diaphragm pressure gauge
Sanitary Diaphragm Pressure Gauge
I-shape Diaphragm Pressure Gauge
Flange connection Diaphragm Pressure Gauge
Flange Connection Diaphragm Pressure Gauge

BCST Is Your Best Partner For Diaphragm Pressure Gauge in China

Diaphragm Pressure Gauge – A Complete Guide

Since 1990, BCST has been manufacturing and supplying Diaphragm pressure gauges along with a variety of instruments. It has two kinds of connection: one is a flange, and the other is the thread. The accuracy rate of the Diaphragm pressure gauge by BCST is high, and the maximum temperature is 100 degrees Celsius. Our valuable customers select the Diaphragm pressure gauge with the combination of the separator depending on the environmental conditions.

Following are the answers in detail regarding the questions about the Diaphragm pressure gauge:

Q1 – What is a Diaphragm pressure gauge?

The Diaphragm is an elastic material, and if you apply pressure, then you can displace it. This type of pressure gauge has elastic property due to Diaphragm for determining the variation between the unknown and reference pressure. The Diaphragm pressure gauge works similarly to the bourdon gauge. But if you fit the Diaphragm pressure gauge, then the Diaphragm deforms due to elasticity. The Diaphragm pressure gauge is primarily useful because it requires less space. A Diaphragm pressure gauge is usually suitable for low-pressure applications. There is a thin disc present in this device and can blow the pressure in the outer direction. Diaphragm’s design is so that the characteristics of pressure and deflection are linear as much as possible and less shifting towards the zero points. The Diaphragm pressure gauge helps measure the gases and liquids.

Q2 – What are the types of Diaphragm pressure gauges?

  • Capillarydiaphragm pressure gauge: The use of this Diaphragm pressure gauge is when the sensitive element of measuring the pressure is not in contact with the process of the medium. The connectivity with the capillary tube is essential because the location of the pressure gauge has to be better for the visibility of the operations.

figure1 Capilliary-diaphragm-pressure-gauge

  • SanitaryDiaphragm Pressure Gauge: In this Diaphragm pressure gauge, there is an integration of an element whose purpose is to display the status. Mechanically, it transmits the pressure without the transmission of the fluids. The sanitary diaphragm pressure gauge is applicable in pharmaceutical industries for the measurement of hygienic pressure.

figure 2 Sanitary-diaphragm-pressure-gauge

  • Anti-shock Diaphragm Pressure Gauge: This type of Diaphragm pressure gauge is suitable for measuring the pressure in the machinery process. Like homogenizer machines, crushers, and other machines related to the food. The anti-shock Diaphragm pressure gauge has high reliability and is anti-corrosive. You can easily install this Diaphragm pressure gauge, and it is shock-proof as well.

figure 3 Anti-shock-Diaphragm-Pressure-Gauge

  • Thread Connection Diaphragm Pressure Gauge: the overall performance of the thread connection Diaphragm pressure gauge is good enough. Even the installation process of this Diaphragm pressure gauge is relatively easy. This Diaphragm pressure gauge is also shock-proof and prevents corrosion. Therefore, it is suitable mainly for homogenizers and other applications similar to it.
  • Capillary Sanitary Diaphragm Pressure Gauge: A capillary tube in the Diaphragm pressure gauge enters the gas through the needle. It is not easy to clean them and prevents the Diaphragm pressure gauge from working. So, the capillary sanitary Diaphragm pressure gauge is of stainless steel helps separate the capillary tube and remaining contents of the tank.
  • figure 5 Capillary-sanitary-diaphragm-pressure-gauge
  • Bottom Connection Diaphragm Pressure Gauge: This Diaphragm pressure gauge is steel, and the connection is from the bottom. It is suitable for corrosive medium and challenging surroundings. The filling of glycerin in the bottom connection Diaphragm pressure gauge smoothens the movement of the gears and other parts.
  • figure 6 Bottom-Connection-Diaphragm-pressure-gauge
  • Stainless SteelDiaphragm Pressure Gauge: stainless steel is helpful in Diaphragm pressure gauges in corrosive surroundings. The connection of the flange is open along with the hygienic environment, especially for the processes in pharmaceutical industries. You can also flush the mounting versions of stainless-steel Diaphragm pressure gauges without transmitting the liquid.
  • figure 7 stainless-steel-diaphragm-pressure-gauge-1
  • I-shape Diaphragm Pressure Gauge: The I-shape diaphragm pressure gauge is of stainless steel. The connection type in this diaphragm pressure gauge is thread and in the radial direction.
  • figure 8 I-shape-Diaphragm-Pressure-Gauge
  • Oil Fill Diaphragm Pressure Gauge: The Diaphragm pressure gauge is of stainless steel and filling with oil, not the dry one. The oil filling Diaphragm pressure gauge has a capillary whose length is 5m. It helps measure the fluids whose temperature is high, easy for solidification, and solid floating of the matter. There is no connection with the pump of the Diaphragm.
  • figure 9 Oil-Fill-Diaphragm-Pressure-Gauge
  • PTFE Liner Diaphragm Seal Pressure Gauge: The manufacturing of a Diaphragm pressure gauge with the PTFE liner and lining of the Diaphragm is for the protection from high-corrosive media.
  • figure 10 PTFE-Liner-Diaphragm-Seal-Pressure-Gauge
  • Electric Contact Diaphragm Pressure Gauge: The particular type of Diaphragm pressure gauge with the electrical contact controls the output. The signals as output help in operating, maintaining, and alarming the device. You can also use the diaphragm seal in this Diaphragm pressure gauge for managing the corrosive processes.figure 11 Electric-Contact-Diaphragm-Pressure-gauge
  • Flange Connection Diaphragm Pressure Gauge is primarily applicable in chemical industries, food, and other areas. The range for measuring the pressure in the flange connection diaphragm pressure gauge is medium but helps high process pressure. It is suitable for handling harsh environments. You add the rinse hole in this Diaphragm pressure gauge for cleaning efficiently.figure 12 Flange-connection-Diaphragm-Pressure-Gauge
  • Q3 – What is the working principle of the Diaphragm pressure gauge?


    The Diaphragm pressure gauge is the device that uses the Diaphragm with the specific pressure for measuring the pressure in the fluid. The Diaphragm pressure gauge is helpful for many purposes, such as measuring the atmospheric pressure, recording the power of the vacuum in the vacuum pump, or inspecting the pressure in the canister of the gas. The Diaphragm pressure gauge has a membrane in a circular shape that has a sheet of steel in particular dimensions. The membrane is either flat or slightly wavy. The Diaphragm pressure gauge connects with the transmission that amplifies the deflections of the Diaphragm pressure gauge and proceeds towards the pointer. Apply the processing pressure on the lower side of the Diaphragm while the upper portion is at the atmospheric pressure. Here arises the differential pressure around the Diaphragm and lifting it. Keep the pointer in motion, and the Diaphragm deflection is a minimum of at least 1 mm. Using the high-ratio to increase the movement and make the pointer rotate with the full-scale length is essential. There is a possibility of transmitting a high-ratio mechanism so that the Diaphragm can generate large forces.

    Q4 – What are the advantages of using a Diaphragm pressure gauge?

    There are three main advantages of using a Diaphragm pressure gauge which is as follows:

    • Measuring the low pressure: the Diaphragm pressure gauge is also known as a specialist in processing industries. The starting measurement of pressure in the Diaphragm pressure gauge is 16 bar to the maximum value of an average 25 bar. The lowest measuring value to achieve is approximately 600 mbar. You need to check the specifications of the Diaphragm pressure gauge whether the measuring range is in “bar” or “mbar.” The larger the diameter of the Diaphragm, the lower the pressure is available for the measurement. When the pressure is below 16 mbar, the elements of the Diaphragm are pressing their limits. They need to be thin at an extreme level to receive elasticity. To resolve this issue, use a particular Diaphragm pressure gauge: a capsule shape pressure gauge.
    • Safety regarding the high level of overpressure: The Diaphragm pressure gauge and its elements help protect from the overpressure. The Diaphragm provides support from the upper side of the flange. The contour along the flattening waves along gives protection along the greater area for the contact. The Diaphragm pressure gauge has five times standard overpressure safety from the value of full scale.


    • Usage in the critical medium: The Diaphragm in the Diaphragm pressure gauge is resistant to aggressive substances. Its element has a foil from the unique material stick to it and gold plating to galvanize. Especially in an aggressive medium, you can align the lower flange of the Diaphragm. Therefore, the area becomes in contact with the product and provides protection. The Diaphragm pressure gauge helps measure the involvement of crystallizing, contamination, or viscous medium. These mediums can clog the pores of little pressure and internals of the tube. To avoid the issues, the Diaphragm pressure gauge connects with the process through the open flange. This helps in generating the chamber for more considerable pressure so no medium cannot settle in it. For operating sanitary applications, there is an availability of a variety of flush diaphragms.

Q5 – What are the specifications of the Diaphragm pressure gauge?


The standard size of Diaphragm pressure gauge 100 mm and 160mm
The accuracy rate of the Diaphragm pressure gauge 1.6
Range of scale in Diaphragm pressure gauge · 0….160mbar to 0….250 mbar

· 0….400mbar to 0….25 bar

· Or equal to the other vacuum or combination of the pressure with the range of the vacuum

Limitation of the pressure in Diaphragm pressure gauge · Steady: value in full scale

· Fluctuation: 0.9 multiply the value of full scale

Overloading safety 5 multiply by the value of full scale, although the maximum value is 40 bar
Permissible temperature · Ambient: -20 degrees Celsius to 60 degrees Celsius

· Medium: maximum temperature is 100 degrees Celsius

· For storage: -40 degrees Celsius to 70 degrees Celsius

(The range in the scale is less than 60 bar: -20 to 70 degrees Celsius

The effect of the temperature in Diaphragm pressure gauge When there is a deviation in the temperature of the Diaphragm pressure gauge from the reference temperature
Connection of the process with the lower measuring flange Stainless steel 316L
Movement in Diaphragm pressure gauge Stainless steel
Material of dial-in Diaphragm pressure gauge White, aluminum, and black lettering
Pointer Black, aluminum
The case along the measuring upper side of the flange Stainless steel on the safety level, with blowing out the device and instruments filling the liquid along with the compensation valve towards the vent case
Window in Diaphragm pressure gauge Lamination on the safety glass
Material of ring in Diaphragm pressure gauge Stainless steel and bayonet ring
Filling of the liquid in Diaphragm pressure gauge A mixture of glycerin and water.


Q6 – What are the applications of a Diaphragm pressure gauge?


The Diaphragm pressure gauge is suitable for handling difficult kinds of medium like vicious, aggressive, or contamination. The bayonet ring is stainless steel in a Diaphragm pressure gauge whose special design is resistant to rust and sealing the case from highly resistant chemicals due to a dirty/damp atmosphere.  The Diaphragm pressure gauge helps in measuring the points with the increase of the overloading. The Diaphragm pressure gauge can also handle cases of flailing the

liquid appropriate for high pressures and vibrations. In the most aggressive environments, you can use a Diaphragm pressure gauge.

Many industries use Diaphragm pressure gauges for their process and applications:

  • Mining, power plants, chemical, and petrochemical
  • In environmental technology and on/offshore
  • In building the machines and generally constructing the plant.

Q7 – Which type of Diaphragm is suitable for Diaphragm pressure gauge?


There must be linearity in the deflection of the Diaphragm as the pressure increases along with the deflection simultaneously. The steel material is in the flat Diaphragm that will be linear only if the deflection is small. There is no linearity in the flat Diaphragm due to the large deflection and receiving more stress on the Diaphragm. So, it becomes stiff. Most industrial applications use the corrugated metal diaphragm to conduct the processes. It assures to make the linear deflection and become more elastic while comparing with the flat Diaphragm.  The Diaphragm pressure gauge along the opening flange helps in handling the vicious kind of liquids.

Q8 – What is the difference between the bourdon tube and Diaphragm pressure gauge?

Diaphragm pressure gauge: The element in the Diaphragm has two membranes and the connectivity of two waves. The pressure of the measuring medium works inside the cavity of the capsule. The deformation, as a result, is helpful indirectly measuring the medium’s pressure and the value of the pressure indicates towards the pointer. The Diaphragm pressure gauge helps measure the gas and measures the micro-pressure/over-pressure protection to a particular extent. When the sensitive parts stack together, there is a significant force for measuring the small pressure. The usage of a Diaphragm pressure gauge starts when the bourdon tube pressure gauge is reaching its limits.

Bordun tube pressure gauge: The sensitive part of the bourdon tube pressure gauge is an elastic C-shape tube that bends into an oval cross-sectional area. The pressure of the existing medium works inside of the wave tube. In this manner, indirectly, the cross-section of the bourdon tube becomes circular. As a result, there is stress in the ring due to the deformity in the bourdon tube. The stress causing in the ring makes the bourdon tube move in the outward direction. The amount of the deformation is dependent on the pressure of the measuring medium. Therefore, it displays that it is indirectly moving the pointer by the movement.

Q9 – How to calibrate the Diaphragm pressure gauge?

Before installing the Diaphragm pressure gauge, check the Diaphragm’s material and its measuring range. Mostly, the process of calibration in the Diaphragm pressure gauge is similar to the traditional pressure gauge. But it is a little bit different from some aspects which are as follows:

  • Before proceeding towards the calibration, you first need to prepare the matching joint depending on the Diaphragm pressure gauge model that needs to be used in the calibration table. Mostly the device of the Diaphragm in the Diaphragm pressure gauge is a flange. So, all the preparations of the pressure fittings are according to the size and kind of the flange. Then, you can find the pressure joints while processing which is the easiest method.
  • Check and follow the calibration table for the process of fixing the Diaphragm pressure gauge. Handle the Diaphragm pressure gauge gently, and don’t touch the Diaphragm gently. I stuck the wrench while rotating the Diaphragm pressure gauge. The pressure gauge and Diaphragm have a system for sealing. Please don’t replace the Diaphragm pressure gauge, stopping the flowing fluid inside the system from the leakage.
  • In the process of boosting, check if there is any leakage of oil or sealing. If you see any leakage of oil or seal is not correct, return the Diaphragm pressure gauge to the manufacturer. If the situation is different, remove the indicator needle and set it again. For using it for the long term, fix the needle again at ½ range.

Q10 – What are the features of a Diaphragm pressure gauge?


  • The whole case and wetted parts of the Diaphragm pressure gauge are of stainless steel.
  • A whole variety of materials are available for the Diaphragm in Diaphragm pressure gauge.
  • There is an availability of high overload range safety in Diaphragm pressure gauge approximately to 10-fold full scale.
  • In Diaphragm pressure gauge, process connection by thread or open flange
  • The scale in the Diaphragm pressure gauge ranges from vacuum to 60 mPa
  • In the Diaphragm pressure gauge, the PTFE liner is present for handling the corrosive medium
  • There is a case and bayonet ring in the Diaphragm pressure gauge of stainless steel to blow out safely from the back.
  • In the Diaphragm pressure gauge, a membrane to equalize the pressure is also available.

Q11 – What are the points to consider while selecting Diaphragm pressure gauge?


  • Select the Diaphragm pressure gauge according to the accuracy need by the application
  • Range of operating the pressure and temperature in Diaphragm pressure gauge
  • The consideration of pulsation, vibration, and shock is important in a Diaphragm pressure gauge.
  • Composition of the pressure in the fluid
  • Requirements of mounting in Diaphragm pressure gauge
  • Consideration of the size of the dial-in Diaphragm pressure gauge
  • Concern about the compatibility of the chemical with the construction of the Diaphragm pressure gauge
  • Choose the type of Diaphragm pressure gauge according to the need of your application
  • Check the Diaphragm pressure gauge’s location near the tapping place, receiving the temperature and pressure properly.

Q12 – How to install a Diaphragm pressure gauge?


The location of the Diaphragm pressure gauge must be near the tapping place, so the Diaphragm pressure gauge receives the temperature and pressure properly. There is a need for proper sealing in the Diaphragm pressure gauge with the help of appropriate sealing rings. The diaphragm seals help in separating the pressure medium that is harmful to the element of the Diaphragm. The connectivity between the seals of the Diaphragm and Diaphragm pressure gauge has to be proper. The main part of the Diaphragm pressure gauge in single Diaphragm in the circular shape clamping between the flanges. The diaphragms in the Diaphragm pressure gauge are hollow and flat discs on the wavy surface. The pressure applying in the Diaphragm pressure gauge transfers towards the pointer through the pivots, gears, and levers.

Final thoughts:

The Diaphragm pressure gauge is known for amazing load performances. There are different types of Diaphragm pressure gauges available at BCST whose body is full of stainless steel. Even unique materials are also available for sealing the Diaphragm. The Diaphragm pressure gauge of BCST is useful in measuring the pressure with high viscosity. BCST delivers the Diaphragm pressure gauge according to the requirements of the customer. It also depends on the flowing and surrounding conditions. You can choose the type which suits your application. Stop thinking and order the Diaphragm pressure gauge at BCST. Our customer representatives are available 24/7 to assess, resolve your queries and provide a quotation. Call us on the official number or mail us. For a quick response, you can fill an online form. BCST is always delightful to serve you.


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