I. Structure and use

Medium-pressure single-port exhaust valve valve body is drum-shaped, the valve internal including floats, brackets and sealing ring and so on. The valve is installed at the pump outlet or in the water distribution pipeline to exclude a large amount of air collected in the pipeline, or the air collected at the higher part of the pipeline is discharged to the atmosphere, in order to improve the efficiency of the pipeline and the use of water pumps. When negative pressure occurs in the pipeline, it can automatically suck air at high speed to ensure the safety of the pipeline and avoid the damage caused by negative pressure.

　　II. Principles of operation

When the pipeline begins to fill with water, the float is in the open position, carrying out a large amount of air exhaust. When the air is discharged, the inner cavity of the valve is filled with water, the float rises and drives the sealing ring, so that the exhaust valve automatically closes and stops exhausting. When the normal delivery of water in the pipe, such as air gathered in the valve to a considerable degree, the valve water level drops, the float falls, the air will be discharged. When the pump stops, the water flow in the pipe is empty or negative pressure is generated in the pipe, at this time, the valve flap opens quickly to inhale the air to ensure the safety of the pipeline.

　　III. Main technical parameters

Model: PQ43X;

Nominal pressure: PN40;

Valve body test pressure: 4.0Mpa

Seal test pressure: 4.0Mpa

Applicable temperature: 0～80℃

Applicable medium: water

Fourth, the exhaust valve installation location map

1, the pump outlet, before the check valve on the cross-pipe, in the pump start exhaust, stop the pump suction;

2, pipeline downhill, when the pump is stopped, may cause vacuum (or negative pressure) at;

3. At the breakthrough; and

4, long-distance slow ascending (descending) slope without the highest point of the pipeline, every 0.4 ~ 0.8 kilometers to set the exhaust valve.

5. Composite exhaust valves are installed at the highest point of each uphill slope.

　　V. Installation Precautions

1, the exhaust valve should be installed vertically on the cross-pipe, the deviation is not more than 2 degrees;.

2, in order to facilitate maintenance, the exhaust valve should be installed below an isolation valve (soft sealing gate valve, butterfly valve, etc.);;

3, winter exhaust valve should take anti-freezing measures.