Private Well

Hilly

Quick question/poll:
Where do you guys install check valves on private wells. I have some people telling me the ideal spot is attached to the pitless adapter. I personally thought attached to the tank tee was most common. Anyone have any thoughts? Or does anyone have any code reference/requirements.

The only thing I see (for Canada anyway) is where people use Poly Lines that are rated for Cold Water only the check would have to be downstream of all the Poly. (Commonly the transition happens at the tank tee)
Thanks for any thoughts or insight.

MikeG

Is this a submersible pump, deep well jet pump or shallow well pump? Most submersible pumps have a check valve at the pump discharge. There are recommendations to install additional checks in the line every so many feet of pipe, not sure of the distance specified. Usually if the well is deep or the well is a distance from the house. Additionally there are recommendations for a check at the tank tee. I have a check in my submersible, pump is at 45; depth, line to house is about 75' with another check at the tank tee. When I had a shallow well pump in the house the only check was the foot valve at the bottom. Some say that on long lines additional checks may help in the water hammer when the pump shuts off. I'm in northwestern Ohio and this what is generally accepted here. Is it a code, state, county etc. don't know. Mike

Jamie Hall

If this is a submersible pump, there must be a check valve at the outlet of the pump -- down in the well. In my experience, there really shouldn't be any other check valves, or if they are they must be spaced so that they are no more than 15 feet in elevation difference from one to the next, since you don't want to pull a vacuum anywhere on your supply pipe -- and check valves often leak.

As to water hammer... on longer supplies this can be a problem, although most pumps do not build head fast enough when they start, and a check at the pump will prevent that backflow. However, the location of the pressure switch is critical: it must, no ifs, ands or buts, be located at the pressure tank(s).

All this assumes that you have the usual diaphragm or bladder type expansion tank. If you have a hydropneumatic tank with an air control on it (unlikely -- most of them have died years ago) there are different rules...

ChrisJ

Jamie Hall said:

If this is a submersible pump, there must be a check valve at the outlet of the pump -- down in the well. In my experience, there really shouldn't be any other check valves, or if they are they must be spaced so that they are no more than 15 feet in elevation difference from one to the next, since you don't want to pull a vacuum anywhere on your supply pipe -- and check valves often leak.

As to water hammer... on longer supplies this can be a problem, although most pumps do not build head fast enough when they start, and a check at the pump will prevent that backflow. However, the location of the pressure switch is critical: it must, no ifs, ands or buts, be located at the pressure tank(s).

All this assumes that you have the usual diaphragm or bladder type expansion tank. If you have a hydropneumatic tank with an air control on it (unlikely -- most of them have died years ago) there are different rules...

Hi Jamie?

Why not? What harm will a vacuum, no matter how strong do to the pipes?

ChrisJ

JUGHNE

A vacuum leak in the supply line could pull in contaminated ground water that the horizontal supply lateral line might be buried in.

You can have vacuum leaks in piping that will not show up when that piping is pressurized.

Jamie Hall

The problem with a vacuum in the supply pipe, @ChrisJ , is the possibility of pulling contaminated water in from the surrounding soil should there be small leaks in the supply line. Miniscule, I'll grant you...

The idea of intermediate check valves is actually a very good one, provided they don't leak and are accessible (such as on the drop pipe). Buried underground somewhere, not so much. The diagram you provided is correct; I tend to forget about wells which are very deep to static water, as most of my work on wells has been in New England, where that doesn't happen!

Hilly

Thanks for all the responses guys.