Automatic Air Vents

[Dymalica]

I got two questions about this device:

1. When the piping system is drained, does the automatic air vent open up to let air into the system to allow the water to be drained? If the ball drops down when the water is drained, I would think it would let air in.

2. Does it only vent out air when the system is stopped and air has time to accumulate in the reciever? Or does it vent all the time?

Thanks

 

[KiwiMace]

The typical float AAV closes against the seat on rising water level, air above the water level is vented. On falling water a non-return ball stops air being sucked in.

It only vents when air accumulates, allowing the ball to drop and away from the seat.

For example:

http://www.bellgossett.com/literature/files/10.pdf

 

[insult2injury]

A combination air/vaccuum valve will do both functions.

I2I