QB1 single-port auto-exhaust valve mainly made up of body、valve、cover、stem、float、exhaust nozzle and so on. Used in small diameter pipes( diameter φ50-200), for exhausting, ensure pipe be without holding breathing、air-resistance, if power is out, inside pipe will produce negative pressure, automatic inspirate to protect the safety of pipeline

Working principle:

When need to discharge gas of pipe, the air under water pressure ,get into the body cavity, and discharges from the exhaust nozzle, along the water of pipe filled body cavity, so that the float under the action of water buoyancy, Move to block the exhaust nozzle, achieve self-sealing, pipe in the normal line, the air in water under the action of pressure, constantly discharged into the upper body cavity of the exhaust valve, forcing float down from the original sealing position, when the air and from the exhaust discharge nozzle, with the attendant, then float back to the original position from the seal, therefore, exhaust valve in the valve during normal operation is always open, and float repeated the action, air is discharged.

When you need repairing or cleaning the body cavity, the valve should be closed.