What is a Diaphragm Pressure Gauge

Diaphragm pressure gauges are also known as micro-pressure gauges. It is suitable for measuring low micro-pressures of liquids, gases, or vapors that are not explosive, crystallize, solidifies, and have no corrosive effect on copper and copper alloys. The diaphragm box pressure gauge uses a diaphragm box as a sensitive element for measuring small pressures. It is used to measure the micro and negative pressure of gases that do not corrode copper and copper alloys and do not pose an explosion risk. It is widely used on boiler ventilation, gas pipelines, combustion devices, and other similar equipment.

banner 1 -diaphragm pressure gauge

1. Working principle

The instrument consists of a measuring system (including fittings, corrugated diaphragm, etc.), a drive mechanism (including lever mechanism, gear mechanism), indicating parts (including pointer and dial), and a housing (including case, liner, and glass). The working principle of the instrument is based on the fact that the free end of the corrugated diaphragm is deformed by the pressure of the measured medium, which is then driven and amplified by the gearing mechanism. The measured value is indicated on the dial by the pointer fixed on the gear shaft. There is also a zeroing device for easy adjustment of the zero position.

The measuring range of the diaphragm pressure gauge is -80~60000Pa. However, different diaphragm pressure gauges should be used according to different pressure ranges. It is recommended to use a disc-type diaphragm pressure gauge when the pressure is -1000Pa~60000Pa is -80Pa. It is recommended to use a rectangular diaphragm pressure gauge.

2. Technical Instructions

Main technical specifications of the diaphragm box pressure gauge

1. Scale range and accuracy class and weight.

2.Measuring range:(kPa)

0~2.5;0~4;0~6;0~10;0~16;0~25;0~40;0~60;-2.5~0;-4~0;-6~0;-10~0;-16~0;-25~0;-40~0;-2~2;-3~3;-5~5;-8~8;-12~12;-20~20 -30~30

3. Resistance to working environment vibration: V-H-3 class.

3. Stainless steel diaphragm pressure gauges

Stainless steel diaphragm pressure gauges are stainless steel according to the pressure guide system and the housing. It is used to measure gas media’s micro-pressure and negative pressure in processes with high corrosion resistance requirements.

Stainless steel diaphragm pressure gauge concerning the structural characteristics of the original diaphragm pressure gauge and the development of corrosion-resistant micro-pressure gauge. It is used on equipment such as boiler ventilation and gas pipelines to measure various gas media’s micro and negative pressure in processes with high corrosion resistance requirements.

Flush flange diaphragm stainless steel pressure gauge

4. Stainless steel diaphragm pressure gauge features 

4.1 stainless steel anti-corrosion type and oil-filled shock-resistant type suitable for various measuring environments.

4.2 With φ60, φ100, φ150 and other outside diameter sizes including axial, radial direct installation; axial, radial front flange, rear flange installation, axial U-type clamps, unique medical installation, and other different installation forms.

4.3 A wide range of positive, negative, and combined positive and negative pressure measurements, from 500 Pa to 100 KPa in any content.

4.4 Provide a variety of alternative items to carry out the characteristics of the production fully.

Stainless steel diaphragm pressure gauge with anti-corrosion characteristics, diaphragm material, and joint material are SUS316, or SUS304 is mainly used to measure the corrosive gas of the slight pressure.

5. The application and use of the diaphragm  pressure gauge

Diaphragm pressure gauges are suitable for measuring micro and negative pressures that do not corrode copper alloys and do not pose a risk of explosion. Gases are widely used in equipment such as boiler ventilation and gas pipelines, and the diaphragm box pressure gauge can be installed in situ and indicated on site. The difference between a diaphragm box pressure gauge and a pressure gauge is as follows.

5.1 Common pressure gauges are used to measure the pressure of non-oxidizing liquids gases etc.

5.2 Diaphragm pressure gauges are usually used in two ways.

5.2.1 Measurement of oxidation-resistant applications for pressure measurement (the measured medium has oxidizing properties, different oxidizing media should adopt other diaphragm materials)

5.2.2 Food hygiene application, due to the standard pressure gauge in the measurement of pressure when the measured medium in the pressure gauge external non-movement, repeated infection. The size of the diaphragm pressure gauge is to adopt the indirect measure, the membrane box pressure gauge in the measured medium pressure induction to create a deformation, sealing liquid is pressed, constituting a pressure equal to P, conducted to the pressure instrument, reveal the measured medium pressure value. Suitable for measuring viscosity, easy crystallization, oxidation, high-temperature liquid, gas, or granular solid media pressure. Membrane box pressure gauges are available in a wide range of raw materials to suit various oxidizing media.

6. Conclusion

The diaphragm pressure gauge is intended as an instrument based on the proven membrane cartridge measuring system. The diaphragm box measuring principle is particularly suitable for low-pressure conditions. When pressurized, the diaphragm element expands to the incident pressure, and the expansion signal is transmitted to the movement and displayed on the dial. The housing and bayonet ring are made of stainless steel. The process connections are made of copper alloy.

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