PSW

Moved last fall and when I went to turn on gate valve in shop for the first time this week to irrigation system I found several issues and had to immediately turn off the water to sprinkler main. In first 25 feet of main line leaving shop I had 3 repairs total. Fix one find another. System doesn't appear to have any leaks now and 3 very large holes have been filled and raked over. I still have a few heads I want to move and of the 14 zones I only plan on using maybe 4 or 5 zones moving forward. I believe the mature hedges and shrubs will be fine surviving our short summers in the PNW. During the repairs we tested the water pressure to irrigation system as it left the shop and it was 135 psi. The water as it feeds the house as a PRV and I also have a PRV in shop for interior supply. But No PRV for irrigation system. Will I continue to have issues with leaks and schedule 40 PVC not being able to handle the pressure or with 14 zones is this the kind of pressure needed to operate such a large system? Thanks for the input. My hope is if I blow it out each winter I am ok to leave as is because the current layout of pipes in my shop doesn't leave much room in design to fit a PRV valve without a lot of headache.

Stim

What is the source of the water supply?
That seems really excessive!
With the numerous motorhomes I have owned I always used a pressure regulator (IIRC 45 psi) when hooking to shore water.
My well is set at 60 psi for my home.

jacobhchandler

Too high, will damage valves. Needs regulator.

captainbaker

Waaaay to high. You will blow out joints and sprinkler heads over time..

Bison

“Normal” municipal water pressures are between 90 and 100 psi. While house hold pressure is usually about 60 psi.

SeaCat22

Wow, y'all have high domestic pressures.
You may blow a seal.
Maybe it was just some ice cream.

PSW

I was borrowing a gauge when I measured. Going to get my own tomorrow and test a few spots. If it is in fact135 I will leave off until I get a PRV in system. I knew it was high for a home and not a chance on a boat but was hoping that for a irrigation system it may have been acceptable.

cphilip

I remember that joke... A classic.

xlr8ngn

May have been designed for 135psi. You can throttle back on the valve when it operates and see how it responds when the gauge is at lower pressures. A zone has to be operating while you do this.

dssmith

When I blow out my sprinklers with my air compressor I only use 60psi. That's what's recommended. Does the job nicely. Call or google the supplier of you solenoid manfacturer and start there.

airbrush

Most sprinkler heads aren't rated for 135 PSI

jbooker9

This will not effect the presure only the volume,There will still be 135 psi on the system.

acme54321

No it won't,i a zone is operating everything behind the valve will be at a lower pressure.

99yam40

depends on how much the zone flows and how much the valve is closed.
if the system is designed to run multiple zones at once and has large valves there may not be enough flow with one zone on to drop the pressure

jbooker9

Everything after the sprinkler valve is opperating at a lower pressure already. As I already stated throteling a valve, controls volume not pressure it will still be 135 at the sprinkler valves when the system is not running. If you need to control volume you would do that at the sprinkler valve not the supply.

colecaz

You might want to check the pressure in your house, too. That's awful high.

jbooker9

Really a PRV should be installed. Your sprinkler valves are probably rated at 150 psi and your at 137 now. If that is the gate valve for the system I highly doubt you are running 2 zones at once.

PSW

The house has a dedicated PRV. The shop also has a PRV. Why they didn't install a PRV for irrigation is tough to figure out. I bought a psi gauge this morning and tested several places. I have two exterior hose bibs and the irrigation system at full pressure of 130 to 135. Everything else is set at 80psi. I ran the sprinklers today and I think the valves are taking the load and reducing to sprinkler heads and they actually run pretty nice other than a few heads needing to be moved. The system would definately benefit from reduced pressure but I am hoping to be able to run it for a while until I can line up a plumber.

Primary Zone



Sprinkler System blowout pressure check valve


House Pressure

jbooker9

You can run it for awhile like it is, your valves should be rated at 150 psi and the pipe around 2 times that. Unfortunately the glue joints are the week points on irigation systems.

JoCo34

It is a little high but it will be fine. We run some larger commercial systems at 120+, biggest thing to look for is misting at the heads. if it's putting out a mist in the air your just wasting that water as it's not falling to the ground. We don't know but the system could have pressure compensating heads which will operate at 45 psi