purpose

In order to make the universal pressure gauge suitable for measuring the pressure of media with strong corrosion, high temperature, high viscosity, easy solidification, and solid particles, as well as situations where it is necessary to avoid direct entry of the measuring medium into the universal pressure gauge and prevent sediment accumulation and easy cleaning, a series of diaphragm gauges composed of a diaphragm isolator and a universal pressure gauge must be used.

Diaphragm gauges are mainly used to measure the pressure of fluid media in the production processes of industrial sectors such as petrochemicals, alkali production, chemical fibers, dyeing, pharmaceuticals, food, and dairy production

Structural principle

When the pressure P of the measuring medium acts on the diaphragm, the diaphragm deforms, compressing the sealing fluid of the pressure measuring system of the pressure instrument, causing it to form a pressure of P - △ P. When the rigidity of the diaphragm is small enough, Δ P is also very small, and the pressure formed by the pressure measuring system of the pressure instrument is close to the pressure of the measured medium.

Specification

·Temperature characteristics of diaphragm meter

Due to the fact that the diaphragm gauge system is filled with sealing liquid as the medium for transmitting pressure, the temperature expansion coefficient of the sealing liquid causes the reading of the pressure gauge to increase as the temperature of the compressed part rises. The temperature effect is related to the expansion coefficient of the sealing liquid, the stiffness of the diaphragm, and the temperature of the compressed part, especially for low range pressure gauges, which have a more significant impact. The temperature error of the general compression part is not more than 0.1%/℃. Therefore, the overall temperature impact of diaphragm pressure instruments is generally the sum of the temperature impact of general-purpose instruments and the temperature impact of the pressure part of the diaphragm device.

·Corrosion resistance of diaphragm meter

The corrosion resistance of diaphragm meters can be ensured by selecting appropriate materials for the diaphragm, flange, and sealing gasket in contact with the measuring medium.

·Diaphragm material: 0Cr17Ni12Mo2 (316)

Monel alloy (Cu30Ni70);

Hastelloy alloy (HC276);

Tantalum (Ta) and Fluoroplastic (F4)

·Flange material: Stainless steel 0Cr17Ni12Mo2 (316);

Stainless steel lined with fluoroplastic (316+F4).

·Sealing hot ring material: Ding Qing rubber; Fluororubber; Silicone rubber and fluoroplastics.

·Selection of flanges: Based on flange standards such as GB (China), HGJ (Ministry of Chemical Industry), DIN (Germany), JIS (Japan), ANSI (United States), and actual domestic use, commonly used flange series standards are compiled for users to choose from. Special orders for other specifications can also be accepted from users

·Selection of sealing fluid: To ensure the reliability and safety of diaphragm meters, suitable sealing fluid should be selected according to different applications.