Acceptance criteria for breathing valves

Pressure test before valve installation 1. In the warranty period, those with the certification and the sealing surface is intact can no longer conduct the strength test alone, but only the air tightness test can be taken before installation. 2. Within the warranty period, it has the certificate, and its sealing surface has defects such as corrosion and damage. After treatment, it must carry out the air tightness test. 3. Outside the warranty period, those with certification and intact sealing surface shall be subject to air tightness test before installation. 4. For valves that need to be degreased and disassembled on site, air tightness test shall be conducted separately before installation. 5. The safety valve shall be sent to the local quality inspection department of the project for verification before the end of installation and commissioning.

The pressure relief of molecular sieve in the purification system is generally rapid in the early stage, not complete and running overtime in the later stage. The pressure relief degree is adjusted by the manual stop valve in front of the pressure relief valve. Through practical adjustment, no matter how it is adjusted, the pressure relief in front is fast, or the pressure can not be exhausted. It is suggested that the valve positioner should be added to the automatic pressure relief valve, and the pressure linear adjustment should be programmed, so that the impact on molecular sieve will be much smaller.