Air Relief Valves on Water Distribution Lines in Subdivision 1

[CivilG]

I am designing a new water distribution system for a new subdivision. The water lines are 6" and 8" diameter C-900. Due to the profile and grade breaks in the road profile, my water lines will have to follow the same profile with slight ups and downs as the grade changes. Question: Is it necessary to install an air relief valve at every high point in the water line, or can some small high points in the water line profile be ignored? Is there a rule of thumb that many engineers use? Thanks, Civil G.

 

[Pinwards]

Typically the utility owner will want ARVs at those high points, so that air can be bled out during filling and removed if air accumulates over time, otherwise it could impede flow. Could you instead consistently slope the pipe to a few number of high points, running it deeper through those localized hi points, and minimum cover at the low points?

There is a velocity at which pipelines will sweep the bubbles along with the flow, but I doubt you are anywhere near that velocity in a residential subdivision.

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[cvg]

fire hydrants also work for filling and bleeding air

 

[cr1973]

CivilG - as cvg mentioned, try to hit your high points where ever hydrants will be installed. Also, you should be aware that c-900 allows for very little, or no, joint deflection at push joints. Put any grade breaks at mechanical, not push, joints. I can't tell you how many designers screw this up!