Anticorrosion of precision pressure gauge shell: 1. The […]
Anticorrosion of precision pressure gauge shell:
1. There is corrosive gas in the operating environment, it is recommended that the outer casing be made of stainless steel or sprayed with PTFE to extend the service life of the pressure gauge;
2. The use environment is high in humidity. It is recommended that the enclosure increase the protection level to prevent external water vapor from entering the gauge and increase the service life of the pressure gauge.
Anti-corrosion of wetted parts of precision pressure gauge:
1. For general corrosive media, if the stainless steel elastic element can withstand corrosion for 1 to 2 years, you can choose a general stainless steel pressure gauge. When installing, the pressure guiding tube should be short. If necessary, the buffer coil should be replaced with a buffer tank to prevent impurities Blocked.
2. If the medium is intended to corrode stainless steel and copper, the buffer tank can be changed to an isolation tank, and corrosion-resistant isolation fluid can be added. The type of barrier liquid can be selected according to the nature of the tested medium, but it is better to not deteriorate after using for more than half a year. If ordinary isolation fluids are not applicable, fluorochloro oil can be used as the isolation fluid, but the price is very expensive, so the isolation tank should be made small, and the fluorine oil should be recycled and reused during disassembly and assembly.
3. Diaphragm pressure gauges can be used. At present, there are molybdenum-containing stainless steel, Hastelloy and tantalum sheets. The pressure is transmitted between the diaphragm and the ballistic tube with methyl silicone oil. The small range can be 0-100kPa. If the diaphragm material is still If it is not resistant to corrosion, a layer of F46 (polyfluoroethylene propylene) diaphragm can be added, but the sensitivity of the instrument is reduced. F46 can also be used directly as the isolation diaphragm, but pay attention to the permeability of the medium. For high temperature and oil-free medium transfer fluid, fluorine oil can be used.