Lake drain back system required parts

[Dom08]

Hello all,
I have seen quite a few posts on drain back systems to prevent freezing but i am looking for clarification on parts needed.
We are pumping water from our lake for our cottage. I cannot get below the frost line as the terrain is too steep and no machinery can be used. We live in Kamloops Canada.
We are installing a new water system for pumping from the lake which consists of: Frank electric 1hp 15gpm submersible water pump. 85 gal pressure tank BLADDER, Tankless hot water tank.
From what i have researched is in order to create a drain back system we require a snifter valve and air control valve located by the pressure tank and a tee connection at the output of the submersible pump with a bleeding valve.
I am having issues finding these parts,
I found one company called the cottage water supply who sells kits but they will not sell their valves only as they "dont make money by selling only valves"

Any clarification or pics will be helpful.
Thanks!

 

[LLigetfa]

Will the cottage be used during freezing weather or will it be Winterized? Snifters and bleeders are very common on well systems that use hydro-pneumatic tanks with Air Volume Controls (AVC). When purchasing HP tanks with AVC, one needs to make sure the AVC can handle the large volume of air due to the long run of pipe. Most AVCs will limit how fast they expel air at the bottom of each pump cycle. If the AVC can be modified so the HP tank holds more water and less air, that is less likely to be a problem.

Also, most snifters and bleeders are not very fast as they are designed to only drain back a few feet of pipe on each pump cycle. A long run of pipe might not drain fast enough not to freeze. Often the run of pipe will be insulated if the system is to be used during freezing weather. A simple check valve or foot valve will work as a high volume snifter but the stronger spring in them will not drain the pipe all the way down to the lake water level.

Another hurdle is to ensure the water in the pipe at the lake surface level does not freeze since the system cannot drain any lower than the lake level.

 

[Sponsor]

 

[Dom08]

It wont be winterized as it will be used in the winter months. We will have external heat wire wrapped around the pipe where it meets the lake.

Our pressure tank has an internal bladder

 

[LLigetfa]

Our pressure tank has an internal bladder

Yes, I caught that but a HP tank could be placed before it to trap the air. Use the lowest possible port on the HP tank for the outlet.

Depending on the volume of air, you might be able to get away with a "high loop" of larger diameter PVC with an air remover at the top of the loop.
https://terrylove.com/forums/index....-air-injection-iron-filter.74384/#post-551972

 

[LLigetfa]

BTW, the following link has a cutaway view of a HP tank with top mounted AVC similar to what I use. I shortened up the tube on the AVC so it removes a foot more air than it is designed to do.
https://www.pentair.com/en-us/produ...ly-pumps/wellmate-hp-quick-connect-tanks.html

The more often the pump cycles, the more air you need to extract so limiting cycling with a Cycle Stop Valve would be a good idea.
https://cyclestopvalves.com/

 

[Valveman]

An air over water tank, (no bladder) is best with a drain back system. You can use a bladder tank if you use a large enough air release valve. With a brass bleeder orifice in the pump line below the frost line, a check valve prior to the pressure tank, and a air relief valve (vent/vac) prior to the check valve, the system will work and drain back. You would need a large enough pressure tank, with a low air pre-charge, to supply water while waiting on the empty pipe to fill after the pump comes on.

An 80 gallon tank holds 20 gallons of water, and will not work as well as a Cycle Stop Valve and a 20 gallon size tank. The 20 gallon tank would hold 5 gallons of water, which should be enough to supply the house while waiting on the lines to fill. A 20 gallon tank is 4 times larger than needed when using a CSV, but would be better than the 80 gallon tank.

With a tankless water heater, the 40 to 60 swing in pressure will make the water heater go on and off as the pump cycles. A Cycle Stop Valve set to hold a constant 55 PSI will solve the water heater problem and deliver much stronger constant pressure to the house than when the pump is constantly cycling on and off between 40 and 60.

 

[Dom08]

Any idea where i can purchase these parts? Large air release valve. Check valves and relief vent/vac valve

 

[Valveman]

Any metal spring loaded poppet style check valve will work. Just put a tee prior to the check valve and install a air vent/vac valve there. You can find a little 1/2" or 3/4" vent/vac valve at any irrigation supply house. I think Netafim and Arkal have them.