Open vent needle valve and bleed air from hose. Then close vent valve.

开启排气针形阀，并从软管排放空气。然后关闭排气阀。

youdao

The solenoid plunger pulls the vent valve down, blocking off the passage to the charcoal canister.

电磁柱塞拉下通气阀，堵住通向活性碳罐的通路。

youdao

The solenoid plunger pulls the vent valve down, blocking off the passage to the charcoal canister .

电磁柱塞拉下通气阀， 堵住通向活性碳罐的通路。

youdao

These valves use a screw type valve instead of a simple flap, and they have a pressure regulating mechanism that will vent water to the ground if the intake pressure exceeds a set level.

FORBES: What Do All The Controls On A Fire Engine Truck Do?