Union type diaphragm pressure gauge Stainless steel 304 or 316

Working principle

When the pressure of the measured medium acts on the diaphragm, the diaphragm deforms and compresses the sealing liquid (such as silicone oil) filled in the gauge. The pressure of the liquid is transmitted to the universal pressure gauge, and finally the pressure value is displayed.

Core Features

• Medium isolation, precise measurement: The diaphragm isolates corrosive, high viscosity, or particle containing media to prevent blockage or corrosion inside the instrument. The sealed filling fluid ensures the accuracy of pressure transmission, especially stable operation under pulsating conditions.
• Flexible, convenient, and easy to maintain: The flexible threaded connection can be quickly disassembled, greatly simplifying maintenance and cleaning work. The diaphragm part with circular arc transition design is not prone to residual media, meeting the hygiene requirements of industries such as pharmaceuticals and food.
• Durable, stable and reliable: The overall material is made of all stainless steel, with good mechanical strength and corrosion resistance. The damping fluid filled inside can effectively alleviate vibration and pressure pulsation, ensuring stable readings.

Selection and Installation Guide

To ensure the long-term reliable operation of the instrument, it is necessary to focus on the following aspects:

• Pressure and temperature range: It is recommended that the working pressure not exceed 3/4 (static load) or 2/3 (alternating load) of the range. The maximum temperature is generally 200 ℃, depending on the sealing liquid and diaphragm material.
• Accuracy and environment: The accuracy level is mostly 1.6 or 2.5. The installation environment temperature is usually between -20 ℃ and+55 ℃, and being too high or too low can affect accuracy.
• Key selection parameters: It is necessary to comprehensively consider the diaphragm material, sealing fluid, connection thread specifications, and special functions (such as shock resistance, electrical contact alarm, etc.).
• Installation points: Before installation, it is necessary to release pressure, drain and clean the interface; Use a wrench to secure during installation to avoid stress on the shell; After installation, it is also necessary to consider the "liquid level difference" error caused by the height difference.

 Material selection for core components

• Diaphragm (contact medium): It should be selected according to the corrosiveness of the medium, and 316L stainless steel is commonly used; Hastelloy alloy is suitable for highly corrosive environments; Monel alloy is resistant to hydrofluoric acid; Tantalum (Ta) is used in extremely corrosive environments; Fluoroplastics (PTFE/F4) are suitable for strong acids and bases.
• Sealing fluid (transmitting pressure): Silicone oil has strong versatility; Fluorine oil is suitable for strongly oxidizing media; Glycerol/vegetable oil is commonly used in the food or pharmaceutical industry.
• Isolators and sealing rings: Isolators are mostly made of 304/316L stainless steel; The sealing ring can be made of fluororubber (high temperature resistant) or polytetrafluoroethylene (PTFE) (corrosion-resistant).

Application field

With its reliable design, this instrument is widely used in multiple industrial fields:

• Chemical and Petroleum: Used for pressure monitoring of corrosive media such as acids, alkalis, solvents, and crude oil.
• Food and Medicine: Used for pressure measurement of hygiene grade media such as syrup and liquid medicine.
• Water treatment and environmental protection: used for pressure measurement of solid particle media such as sewage and mud.
• Special working conditions: such as pressure measurement for municipal construction grouting, high viscosity polymers, etc.