Using irrigation system for garden hose

My house has a 4-zone irrigation system. Three of the zones are sprinklers and the fourth is connected to two hose bibs on opposite ends of the house. I'd like to start using one for watering my garden manually with a hose, but I'm concerned about damaging the system if the pumps on but I'm not continually running the water out of the hose. In other words, if there is nowhere for the water to go when the pump is on (because I am not always spraying water out of the hose), will it damage the system?

 

Depends on the pump, but most irrigation type pumps don't like to be run with the outlet closed. I'm assuming you don't have a pump with a built in pressure tank and pressure switch. The way this is normally handled is to add a pressure relief valve between the outlet and the inlet. PRV is set to a pressure somewhat above normal pressure...say 60PSI. When the normal outlet is closed off, pressure will climb and open the PRV. This allows water to continue circulating through the pump when the outlet is closed. If you anticipate operating the pump with the outlet closed for long periods (say more than 10 or 15 minutes at a time) then the outlet of the PRV should return to the water source (well, pond, whatever) rather than the pump inlet. This is because just circulating the water from outlet to inlet through the PRV for long periods will heat up the water enough that it is bad for the pump. Returning the PRV to the water source allows a constant flow of cool water.

 

Thanks, Paul, that's what I figured. I'll have to do some investigation. Would the PRV be something above-ground, or would I need to get an irrigation guy out here to examine the system? (The system is on a well.)

A simpler solution to my problem is probably to just have a new hose bib on city water installed closer to where I need it.

 

You'd most likely find a PRV valve right at the pump.

You could have a gauge and pressure switch installed to handle the over pressurizing too.