Spec on Air Release Valve Placement 1

[civilcorruption]

Just wondering if there is a general rule as to when to place an air release valve in a water distribution system. I know they are placed at high points in the line, but when is it required? (is there a specific pipe slope or rise that warrants its use?)
I have also heard that if there is a hydrant at the high point, an air release valve is not necessary and also if there is a main stop at the high point, an air release is not necessary. Are these points accurate?

 

[cvg]

a fire hydrant may be useful for initial filling and even for periodic bleeding of air from a system, however, air will collect at the high points and it really requires an automatic valve. In addition, if the line drains quickly due to a break, you run the risk of vacuum collapse of the pipeline unless you install an automatic vacuum release valve at the high points.

 

[cvg]

thread408-89648

check this thread for more info

 

[sokos]

I think that the best design is to install ARV at high points. If there is a fire hydrant at high points, I suggest to move them and put ARV.
In case you have a house connection at high point, then it wis not necessary to put ARV.

 

[stanier]

Go to

http://www.ventomat.com.

Request their software for filling and drainage location of air valves. Beware that all air valve companies want to sell air valves so software is conservative and may specify air valves in a far greater degree than normally used.

Work with Ventomat once you have built your model. They will be able to tell you which air valves can be left off. Some locations it is advisable that a tee is put in case you ultimately need an air valve there. It is a lot cheaper to put a tee in now rahter than later.

 

[jwhite1133]

I work for a construction company who installs water mains and I just recently installed a few ARVs. You can go back later, if determined that an ARV is needed, and install them using a tap and wrap-around. An existing tee is not needed to install an ARV.

Hope this helps you out a bit.

 

[stanier]

Jwhite1133

Modern design techniques recommend a tee at half the main diamter to enable the air to collect where it is exhausted. To say it is not required at design stage results in increased costs to put it in later.

Design the system and have the necessary air valves in place.

A good reference is Advanced Water Distribution Modelling and Management by Haestad (now Bentley).

Geoffrey D Stone FIMechE C.Eng;FIEAust CP Eng

http://www.waterhammer.bigblog.com.au