Overview: In order to expand the range of use of various general-purpose pressure instruments, a diaphragm gauge composed of a diaphragm isolator and a general-purpose pressure instrument must be used to measure the pressure of media with strong corrosion, high temperature, high viscosity, easy crystallization, easy solidification, and solid floating matter, as well as for pressure detection in situations where certain measuring media cannot directly enter the general-purpose instrument and are easy to clean to prevent sediment accumulation. Diaphragm gauges are mainly used for pressure detection in the production processes of industrial sectors such as petroleum, chemical, pharmaceutical, food, and textile. Structural principle: The diaphragm pressure gauge consists of various universal pressure instruments and diaphragm isolators of different structures, forming a closed system filled with sealing fluid. When the pressure of the measured medium acts on the diaphragm, the diaphragm deforms and compresses the sealing liquid in the closed system. Due to the inherent properties of the sealing fluid, the elastic elements in the pressure instrument undergo corresponding elastic deformation and displacement, and the pressure value is displayed by the indicator device. When the stiffness of the diaphragm is small enough, the pressure indicated by the pressure gauge is close to the pressure value of the measured medium. Accuracy: ± 1.6%, ± 2.5%. Diaphragm material: OCr18Ni12MO2(316)， Hastelloy C (H276c), Monel alloy (Cu30Ni70), Tantalum alloy (Ta), fluoroplastic (F4). Isolator material: acid resistant stainless steel, molybdenum containing stainless steel, fluoroplastic. Sealing gasket material: nitrile rubber, fluoroplastic. Sealing fluid: silicone oil, vegetable oil. As long as the technical indicators are: temperature characteristics of the diaphragm meter Due to the filling of sealing liquid as a pressure transmission and medium in the system of the diaphragm meter, the temperature effect of the diaphragm meter is related to the expansion coefficient of the sealing liquid, the stiffness of the diaphragm, and the temperature of the compressed part. The impact on low range pressure instruments is particularly evident. The temperature error of the general pressure part is not greater than 0.1%/℃, so the temperature effect of the diaphragm gauge is generally the sum of the temperature effect of the general pressure instrument and the temperature effect of the pressure part of the diaphragm isolator. The liquid level difference of the diaphragm gauge, especially for those with flexible connecting pipes, will result in a liquid level difference and an impact quantity △ P due to the installation position of the diaphragm pressure part and the universal pressure gauge not being on the same horizontal plane. Pay more attention to precise measurement. 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 gold (Cu30Ni70); Ha Shi Quan Jin (H276C); Tantalum (Ta) and fluoroplastic (F4). Flange material: Stainless steel 0Cr17Ni12Mo2 (316); Stainless steel lined with fluoroplastic (316+F4). Sealing gasket material: Nitrile rubber; Fluororubber; Silicone rubber and fluoroplastics. To ensure the reliability and safety of the diaphragm meter, the appropriate sealing fluid should be selected according to different applications.
