separating house water from irrigation system

[ian morrison]

I want to plumb water into my house using my submersible well pump which also supplies irrigation water to a vineyard. There is plenty of water to handle the needs of both. The problem is I need to isolate the systems to not allow irrigation chemicals in the house. I need suggestions on how to set that up. With a back flow valve on the irrigation supply line I will need some way for the house to activate the pump. Any ideas?
Thanks in advance.

 

[Valveman]

Most states require a Double Check back flow preventer on the inlet to the irrigation line. This will cause a loss of about 10 PSI to the irrigation system, but will keep anything from back flowing from the irrigation to the house. Opening any tap at the house or turning on any irrigation zone valve will draw water from the pressure tank until the pressure switch turns on the pump. 40/60 is the most used pressure setting for house pumps, but maybe more than needed for drip on a vineyard. After the double check a pressure reducing valve can be added if the drip only needs 15-30 PSI.

The main problem with a system like this is the varying amount of flow needed. When using water in the house or irrigation zones that do no use max flow the pump can produce, the pump will cycle on and off, which isn't good. Cycling on and off is what destroys most pumps and many other parts in a pump system. Adding a Cycle Stop Valve will make the pump produce only the amount being used at any given time, and the pump will run continuously, which is a good thing.

 

[ian morrison]

Most states require a Double Check back flow preventer on the inlet to the irrigation line. This will cause a loss of about 10 PSI to the irrigation system, but will keep anything from back flowing from the irrigation to the house. Opening any tap at the house or turning on any irrigation zone valve will draw water from the pressure tank until the pressure switch turns on the pump. 40/60 is the most used pressure setting for house pumps, but maybe more than needed for drip on a vineyard. After the double check a pressure reducing valve can be added if the drip only needs 15-30 PSI.

The main problem with a system like this is the varying amount of flow needed. When using water in the house or irrigation zones that do no use max flow the pump can produce, the pump will cycle on and off, which isn't good. Cycling on and off is what destroys most pumps and many other parts in a pump system. Adding a Cycle Stop Valve will make the pump produce only the amount being used at any given time, and the pump will run continuously, which is a good thing.

View attachment 44520

Most states require a Double Check back flow preventer on the inlet to the irrigation line. This will cause a loss of about 10 PSI to the irrigation system, but will keep anything from back flowing from the irrigation to the house. Opening any tap at the house or turning on any irrigation zone valve will draw water from the pressure tank until the pressure switch turns on the pump. 40/60 is the most used pressure setting for house pumps, but maybe more than needed for drip on a vineyard. After the double check a pressure reducing valve can be added if the drip only needs 15-30 PSI.

The main problem with a system like this is the varying amount of flow needed. When using water in the house or irrigation zones that do no use max flow the pump can produce, the pump will cycle on and off, which isn't good. Cycling on and off is what destroys most pumps and many other parts in a pump system. Adding a Cycle Stop Valve will make the pump produce only the amount being used at any given time, and the pump will run continuously, which is a good thing.

View attachment 44520

 

[ian morrison]

Thanks for the response. I wasn't clear enough in describing my problem. My vineyard irrigation system was installed with the tank and pressure switch down stream from my fertilizer injection device. It looks like the solution is to re-plumb the system with the pressure tank and switch before the injector and the Double Check back flow preventer beyond the pressure switch. That will be a major redoing of the system and I was hoping for an alternative solution. I understand the need for a CSV.

 

[Valveman]

You don't want to inject things upstream of a pump.

I usually see injection into or past a Chemcheck that keeps the injected stuff from being able to back into the pump.