ZZC and the ZZV self-reliant -like difference (micro) presses the regulating valve is one kind does not need the sur- energy the actuator product. May use in nominal pressure PN01, PN10. The difference (micro) presses may partition the adjustment. From 50mm. W.C to 0.1MPa. Its use is very widespread, may use in the industry combustion furnace system, controls two materials, like coal gas, the air flow allocated proportion, reaches the ideal burning. Uses in the hydrogen cold power set sealing the oil system, between the control seal oil and the hydrogen the pressure difference, guarantees the reliable seal. Serves as a petty government official to press valve's low pressure end open to atmosphere namely (difference to press valve negative pressure for the minute pressure valve, end thrust, strength is zero).