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jcom
08-04-2008, 10:13 AM
We installed several PGP's with backflow gaskets and they still leak like crazy.

We are trying to stop about 50' of 1" pipe and about 5' rise from dumping the water out the heads. In the past, just installing the gaskets did the job but these 5 heads all leak to the point of washing the new seed and creating a problem.

Any one having the same trouble? We are looking for help before we swap them out with I-20's.

John

AI Inc
08-04-2008, 10:15 AM
Check valve is supposed to be good for 6 ft of rise . You can try putting in 2 , I have had luck with that in the past. Are you sure there is no debris in the valves?

Wet_Boots
08-04-2008, 10:17 AM
Are all the heads check-valved? Any dirt in the lines? Try a head on a test rig? (a vertical pipe filled with water with the head connected to the bottom with a couple of ells, so you can see how high a column of water it can hold back)

jeffinsgf
08-04-2008, 10:27 AM
Make sure you have the check valve installed correctly. It fits backwards almost as well as it does properly.

jcom
08-04-2008, 10:48 AM
Yep, all the heads are check valved.

News to me that the check valve (gasket) can be installed wrong. It looks identical on both sides to these old eyes.

Will try some more troubleshooting.

John

Wet_Boots
08-04-2008, 11:00 AM
Remove the check from the highest head, and that will help you diagnose a weeping valve.

jeffinsgf
08-04-2008, 11:17 AM
My bad. It is the Hunter Pro Spray check valve that can be installed backwards. The PGP check valve is pretty much impossible to put in backwards. I just remember some serious head scratching when trying to resolve the same issue.

WalkGood
08-04-2008, 12:59 PM
Here is a pic of PGP strainer with check-valve, and a PGP w/o the check-valve strainer basket.

From HUNTER website

The PGP rotor line has an optional built-in
drain check valve in the PGP and PGS, which
can be factory installed. The
check valve is standard on all
12" PGH (30 cm) rotors. A
gray ring around the rubber
cover identifies models
that have the check valve
option. The PGP with the
check valve installed at the
factory is designed to hold back
water to a maximum of 10' (3 m) of elevation
change. This 10' of height is accomplished
by a stronger spring added to the head during
manufacturing. Hunter provides the PGP rotor
with a check valve because stopping low head
drainage eliminates washouts and wasted
water, and may also prevent accidents from
occurring and pests from showing up. Also,
due to water staying in the pipes, installers
may benefit from the reduction of potential
surge damage.
Check Valve Field Installation: The check
valve feature can be added to PGP sprinklers
in the field by ordering Hunter part # 142300.
This field installed check valve will hold back
water to a maximum of 2 ft. (.6 m).

WalkGood
08-04-2008, 01:01 PM
Removing the strainer basket (has no drain check valve).

WalkGood
08-04-2008, 01:04 PM
Strainer w/o check valve next to a drain check-valve strainer. And the PGP guts with no strainer installed.

WalkGood
08-04-2008, 01:05 PM
Simple insertion.

WalkGood
08-04-2008, 01:06 PM
Install done.

WalkGood
08-04-2008, 01:26 PM
You might be able to see the small gap where there is no check-valve installed....

WalkGood
08-04-2008, 01:28 PM
And here you can see the gasket closes the gap.....

Kiril
08-04-2008, 02:29 PM
Remove the check from the highest head, and that will help you diagnose a weeping valve.

Or you could just have someone pull up the sprinkler while you check downstream heads.

jcom
08-04-2008, 05:53 PM
Ok guys, here goes.

Valves are not weeping at all. PGP will not hold the water.

Put in an I-20 and shut if off immediately. Will be changing half a dozen to I-20's to take care of the problem.

Methinks we got a case or two of PGP's with some very weak retraction springs.

Thanks for all the input.

John:rolleyes:

Mike Leary
08-04-2008, 06:04 PM
Put in an I-20 and shut if off immediately. Will be changing half a dozen to I-20's to take care of the problem

I-20's rule.

WalkGood
08-04-2008, 06:20 PM
Ok guys, here goes.

Valves are not weeping at all. PGP will not hold the water.

Put in an I-20 and shut if off immediately. Will be changing half a dozen to I-20's to take care of the problem.

Methinks we got a case or two of PGP's with some very weak retraction springs.

Thanks for all the input.

John:rolleyes:

PGP with the check valve installed at the factory is designed to hold back water to a maximum of 10' (3 m) of elevation change. This 10' of height is accomplished by a stronger spring added to the head during manufacturing.

Check Valve Field Installation: The check valve feature can be added to PGP sprinklers in the field by ordering Hunter part # 142300. This field installed check valve will hold back water to a maximum of 2 ft.(.6 m).

Mike Leary
08-04-2008, 06:27 PM
10' means some pressure loss. Those Hunter "lipstick" LDC's eat 7 psi out of the gate.

Wet_Boots
08-04-2008, 06:47 PM
You could keep the weaker springs and mount the low heads on three foot risers :)

Mike Leary
08-04-2008, 06:54 PM
I don't know what the big deal is; did not the counter jockey ask "Drain or No Drain ?"

jcom
08-04-2008, 07:34 PM
I did not know there was a difference in springs between the different PGPs'. Learn something new every day.

Will be using many more I-20's from now on.

Thanks,

John

bicmudpuppy
08-04-2008, 08:16 PM
Here is a concept I never got.........why did you buy the seperate check? When ever I found a need for a check valve in a head to prevent low head drainage, I just swapped guts with a head that came w/ check. If the head I was replacing was old enough that I couldn't call it new, I charged the customer for a new head. If it was my install or a fairly new head, the head went into the w/o check bin. The w/ check heads stay in a box. Now, (yep, here I go again) the CR500/S800's come with a bag of rubber washers that can be installed if you want the check valve. Memory says the CR500 check is good to 6', but I'm getting old and my memory isn't so good.

Mike Leary
08-04-2008, 08:56 PM
We made it simple, years ago, ALL heads have low-drain checks.

FIMCO-MEISTER
08-04-2008, 09:42 PM
You could keep the weaker springs and mount the low heads on three foot risers :)

cheesy..........

jcom
08-04-2008, 09:54 PM
Ok Bic

I have not stocked PGP's w/ check valve but used the checks as needed, which has been very seldom. Up until now, that is.

Now will have a stock of both style PGPs and of course the I-20's.

John

Waterit
08-05-2008, 12:00 AM
Several pics of what I assume to be Boots' hands (fingers?) fooling with PGP. Still no action shots, down and dirty in the trench.

Still Kiril 1, WB 0.

The ball is in your court, my man.