The double seat regulating valve has two upper and lower seats, so the imbalance force is small. It is suitable for occasions with large pressure difference and low requirements for leakage. The double seat regulating valve with the same caliber can also have smaller requirements for the actuator specification; However, the flow path of the two seat regulating valve is complex, the flow resistance is large, and the adjustable range is small; The valve stem moves up and down, so the valve core has poor stability and large vibration.

The electric butterfly valve with metal seal generally has a longer service life than the valve with elastic seal, but it cannot be completely sealed. If it is a soft seal, it can reach the standard of zero leakage. Of course, metal seals can operate at higher temperatures, while elastic seals cannot withstand high temperatures.