Diaphragm pressure gauge is a widely used pressure measuring instrument in the industrial field. Its core function is to use a special “diaphragm” isolation device to protect the core movement of the pressure gauge from corrosion, blockage, or viscous effects of the measured medium while measuring pressure.
1、 Core role (problem solved)
Ordinary pressure gauges come into direct contact with the measured medium. If the medium has the following characteristics, it will quickly damage the pressure gauge or cause inaccurate measurements:
Strong corrosiveness: Chemical media such as hydrochloric acid, sulfuric acid, caustic soda, etc. can corrode sensitive components inside pressure gauges (such as Bourdon tubes).
High viscosity or easy crystallization: for example, oils, resins, syrups, etc., can block the pressure gauge’s guide hole and internal mechanism, causing the pressure gauge to malfunction.
Containing solid particles or suspended solids, such as mud, sewage, powder, etc., can also cause blockage and wear.
High or low temperature: The temperature of certain media may exceed the normal operating range of ordinary pressure gauge movements.
High hygiene requirements: In the food, beverage, and pharmaceutical industries, measurement systems are required to be easy to clean, sterilize, have no dead corners, and prevent bacterial growth.
The diaphragm pressure gauge is designed to solve the above problems. It serves as a reliable intermediate isolation, accurately transmitting pressure while completely separating harmful media from precision movements.
2、 Working principle
The structure of a diaphragm pressure gauge is mainly divided into two parts:
Diaphragm isolator (process connection part): This is a metal or PTFE film (i.e. diaphragm) in direct contact with the measured medium. It is installed inside a housing with a connection interface (such as a flange).
Pressure gauge movement (indicating part): This is a regular pressure gauge head with elastic components such as a Bourdon tube inside.
3、 Main features and advantages
Excellent corrosion resistance: Different materials of diaphragms (such as 316 stainless steel, Hastelloy, Monel alloy, PTFE coating, etc.) can be selected according to the tested medium.
Anti clogging and easy to clean: The flange connection method (especially the flat embedded diaphragm) makes the medium contact surface smooth and free of dead corners, making it very easy to clean, especially suitable for sanitary occasions.
Wide measurement range: capable of measuring pressure from vacuum to high pressure.
High reliability and long lifespan: effectively protecting the core movement part, ensuring stable operation of the instrument even under harsh working conditions.
Summary：
The core function of a diaphragm pressure gauge is to use an elastic diaphragm and sealing liquid system to accurately measure the pressure of liquids, gases, or vapors while effectively preventing the measured medium from causing corrosion, blockage, or damage to the precision machine inside the instrument. It is an ideal solution for handling harsh measurement conditions in industrial process control. DERKIA company can provide you with qualified diaphragm pressure gauges to help you in various industries.