The difference between the upstream sealed automatic pressure relief valve seat and the double sealed valve seat of the fixed pneumatic ball valve The double piston effect valve seat does not have the automatic ground pressure function, so when no additional relief device is added, if the pressure in the middle chamber rises abnormally, the pressure cannot be released, which will have a certain impact on the safety of the valve. Therefore, the double piston effect valve seat can only be used in stable gaseous media (natural gas, air, ammonia, inert gas, etc.). When transporting liquid media, condensing media and unstable gaseous media, a pressure relief device must be set on the valve chamber. Since the double piston effect valve seat compresses the ball on both sides of the valve seat at the same time when working, the operating force loss is greater than that of the pneumatic ball valve with the self releasing valve seat.

For the fluid with substances easy to adhere, deposit and scale, the flow rate shall not be less than 2 m/s, and it is better to increase it to 3~4 m/s or above, so as to play the role of self-cleaning and preventing adhesion and deposition. For slurry and other highly abrasive fluids, the common flow rate should be lower than 2~3m/s to reduce the wear of lining and electrode. When measuring the low conductivity liquid close to the threshold value, select a lower flow rate (less than 0.5~1m/s) as far as possible. As the flow rate increases, the flow noise will increase, resulting in output shaking.