Just got this house few months back and i have notice that we get water hammering while the sprinkler valve at zone 1 and 2 is turned on. (zone 3,4,5 not having the hammering problem)
The hammering i can hear in the wall by the main water pipe in top , here


Video: https://www.youtube.com/watch?v=k2SMpod0FB0

I have checked the water pressure and is at 47 psi


I have 6 zones:
Zones:
1>front yard > 1" valve and pipe (coming from the ground and going to sprinkler)
2>front yard > 1" valve and pipe (coming from the ground and going to sprinkler)
3>back yard yard > 3/4 valve and pipe (coming from the ground and going to sprinkler)
4>back yard > 3/4 valve and pipe (coming from the ground and going to sprinkler)
5>front yard > 3/4 valve and pipe (coming from the ground and going to sprinkler)
6>not used > 3/4 valve and pipe (coming from the ground and going to sprinkler)


I have also notice that zone 1 there is a drip line connected to it, not sure where but when i start zone 1 i have few sprinkler heads for the grass and also the drip system .
video:
https://www.youtube.com/watch?v=zOFohvubdtE

As for the controller I use the Orbit 57950 B-hyve Smart Indoor/Outdoor 12-Station WiFi Sprinkler System Controller.

I am just trying to figure out if the valves at zone 1,2 are bad?, or to much flow of water goes in or... Maybe add some adapters and convert them to 3/4 water valves?

Looks that there was a mixed water valve brands when i got the house few months ago, i already replaced to water valves at zone 5 and 4 as they where leaking.

Here is few more pictures of the water valve brands that is there now:
https://postimg.cc/gallery/381wbb4pc/

Purchased some 1" pvc pipe and new valves, but before doing anything asking the pro's what you think maybe? the reason with hammering at zone 1,2 and also 1" pipe?! why not 3/4 as others?

Any help will appreciate

Thank you.

 

Any ideas regarding with it may be?
Thanks

 

Where are you checking the water pressure...... at that bib in the picture ?
If yes..... that is after the pressure regulator and is what the house pressure is.
The sprinkler system is not on the regulator so you don't know what that pressure is.

Zones 1 and 2 are 1" lines which means higher flow.
It may be as easy as installing an anti hammer unit where that putty is on the line.

 

You have quite the mix mash of valve and pipe sizes.

Most likely the valve is not bad but the conditions it's operating in are causing the water hammer.

I have a GEOthermal furnace and it took several trial and error purchases to find a slow closing valve that would not cause a loud water hammer when it shut off.

If you can find the brand and model of the valves and do some comparison of operating functions looking specifically for valves identified as slow closing it may help!

 

The water supply for the sprinkler system appears to be 3/4" or 1/2" pipe in the picture. Using 1" on supply going to the zone valves 1 and 2 doesn't buy you anything. I would try reducing the supply pipes going to valves 1 and 2 to 3/4" above or below grade. It appears the sprinkler supply line is missing a check valve to prevent backflow from the sprinklers to the supply line. This is usually mandatory when there is a public water supply. It is a wise thing to install even if you have a well.

 

This problem is a rarity as it hammers when the zones turn on...... not off which is typical.

 

Water line from zone valve to sprinkler head has high spots allowing air pockets to be created when the zone valve opens. When the air pockets reach the sprinkler head, their expansion causes a pressure pulse in the water lines all the way back to the house. Make sure the water supply line is secured where it enters the house (outside and inside). The only other remedy I see is to reinstall the water feed lines from number 1 and 2 zone valves to their sprinkler heads making sure there are no high spots.

 

@Pjmax,
Yes at the main water faucet hose, i just notice that mistake i did and checking the water psi there after that regulator. i may have to find else where to test.
"installing an anti hammer " i may try that too, but will try few things at the water sprinkler valves before i was going to play around the main pipe.

@Mark1
My Zone 1,2 does the hammer while the valve opens On.
I was doing some research about the slow opening and closing valves but not many choices from what i notice.

@beelzebob
I was thinking to add 3/4 sprinkler water valves , then some how i came home with
1" sprinkler water valves! I was going to downgrade from 1" pipe to 3/4 then to add 3/4 sprinkler water valves , maybe this way pressure will be less at the Zone 1 and 2.
I asked homedepot about it, and they told me to add at zone 1,2 a water regulator 30 psi like this one:


but do i need to add that before the sprinkler water valves or after?
Also others mention to adjust the water pressure here :

and see if i still have the hammering (of course i may have to replace the valves with new ones. The ones at zone 1,2 looks kind old, and not sure how to turn psi down or if can be done)
Now , regarding the "check valve to prevent backflow" can that be installed on each zone 1,2 before the sprinkler water valve? i see homedepot has some like this:
https://www.homedepot.com/p/Homewerk...0B4B/202369948
As for the "reinstall the water feed lines from number 1 and 2 zone valves to their sprinkler heads " there is no way i can do that! all the sprinkler valves are in the other side of the house and i think they go under neat my drive way in the other side of the house so i don't think is a option to replace the pipe for the two zones.

Thanks to all for reply with the advice, appreciated!
Will try some this weekend , hopefully i can figure some out.

Regards,

 

I wouldn't reduce the pressure... the zones need the pressure and volume they were designed at. If you reduce the pressure, it's likely the sprinklers won't sprinkle (they'll just dribble). Those pressure reducers are for drip irrigation which requires lower pressure.

Have you considered installing a water hammer arrestor somewhere between the main valve and zone valves? It should help reduce the hammer.

 

Hi, Wow a lot of info here. So here's my two bits. Shut the water off, take apart the valve clean and inspect it pay close attention to the diaphragm. If it looks good put it back together and give it a try.
Good Luck Woodbutcher

 

@Zorfdt
"installing a water hammer arrestor" i am going to look into that also.
Are those arrestors ok if they outside above ground? if temp's goes around 30-35.

@Woodbutcher
Thanks for the advice , i will do it this weekend , before any other to make sure all is clean and the diaphragm is in one piece.

Thanks for advice,

 

I would be concerned with freezing with all the piping and valves, none of them will handle freezing very well. You're right on the edge, it might be safe, but I would probably drain the system in those temps. Do you usually blow out the system in the winter?

 

So i took the two Lawn Genie 1" sprinkler water valves apart, at first i took the right side to see if water will raise up then you know u have a bad valve, all good there. Then i open the left side where the main flow pipe comes in and both valves looks clean and like new. So i guess the valves are ok.
I did try to open kind manual the valves and still does the water hammering , is kind if you open zone 1 and let it run for 30-sec a minute and then shut it off and switch to zone 2 it does it also , but going back in forward it is kind not doing so loud, this is telling me that maybe there is a water back flow because there is no "check valve" installed on the sprinkler main pipe that's coming from the main house water valve.

So i have to dig and install a check valve first and maybe will also install a "T" with a 3/4 tread and cap it, so if the check valve will not work to be able to add a "water hammer arrestor" .

@Zorfdt,
"Do you usually blow out the system in the winter?" my bad about the other post (30-35 ) , we have here above 40's+ during night , rarely goes to freeze and i think no one around here does the blow out on their sprinkler system.
I am in Calif, so for example all week will be 44 and up during night the temp.

Thank you.

 

For got to ask, witch pvc 1" check valve will be good? seen some bad reviews for some at home depot or even amazon.

 

Check your local codes. Most require a backflow preventer valve (PVB) for sprinkler systems instead of a check valve. A PVB is much safer in terms on not allowing dirty sprinkler water flowing back into the house water.

https://www.amazon.com/Zurn-34-720A-.../dp/B00KI0WORE

For the water hammer arrestor, you can either use a commercial one like this, or just use a vertical 12-18" pipe with a cap on top. The air should help cushion the hammer.