QB2 flange dual port exhaust valveDetailed product description：

When QB2 flange dual port exhaust valve needs to discharge gas from the pipeline, the valve stem should be rotated counterclockwise to make the valve stem and valve rise, so that the air in the pipeline enters the body cavity under the pressure of water and is discharged from the exhaust nozzle. With the water in the pipeline filling the body cavity, the floating ball moves upward under the buoyancy of water to block the exhaust nozzle and achieve self sealing. During normal operation of the pipeline, the air in the water is continuously discharged into the upper part of the body cavity of the exhaust valve under the pressure, forcing the floating ball to descend and leave the original sealing position. At this time, the air is discharged from the exhaust nozzle, and the floating ball returns to its original position for self sealing. Therefore, the dual port exhaust valve is always open during normal operation. The float continuously repeats the above actions, and the air is constantly expelled. When maintenance or cleaning of the body cavity is needed, The valve should be closed. This exhaust valve is closed when the valve stem is rotated clockwise.

Main dimensions of QB2 dual port exhaust valve:

Nominal Diameter	Main dimensions (mm)				Applicable Medium
	D	H	H1	L
forty	one hundred and forty-five	three hundred and fifty-five	two hundred and fifteen	three hundred and seventy	water
fifty	one hundred and sixty	three hundred and fifty-five	two hundred and fifteen	three hundred and seventy	water
seventy-five	one hundred and ninety-five	three hundred and sixty	two hundred and twenty-five	four hundred and thirty	water
one hundred	two hundred and fifteen	three hundred and sixty	two hundred and twenty-five	four hundred and thirty	water
one hundred and fifty	two hundred and eighty	three hundred and eighty	two hundred and thirty	five hundred and ten	water
two hundred	three hundred and thirty-five	four hundred and thirty	three hundred and twenty	six hundred and eighty	water
three hundred	three hundred and ninety	five hundred and forty	three hundred and sixty	eight hundred and twenty-five	water

Purpose and main performance specifications

This valve is suitable for discharging all air inside water and hot water pipelines with a temperature not exceeding 100 ℃.

⑴ Note: For pipelines with a diameter greater than 350mm, please choose a single port exhaust valve (QB1-10).
⑵ Install a dual port exhaust valve, and be sure to install a protective valve and ball valve (Q41F-16) underneath to prevent water interruption during inspection.
If the purchaser requests any changes in the size of the exhaust valve flange, please indicate the flange connection size in the contract. This exhaust valve is suitable for pipelines with water, hot water, and a maximum temperature of 100 ℃, to completely exhaust the gas inside the pipeline.

Structure
QB2 exhaust valve is mainly composed of valve body, valve, upper cover, valve stem, float ball, exhaust nozzle, etc.