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  #21  
Old 06-21-2013, 08:43 AM
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Wet_Boots Wet_Boots is online now
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Quote:
Originally Posted by CAPT Stream Rotar View Post
the 70 psi static was ordered my my boss for the longer run of heads away from the POC.

the install was done yesterday so only time will tell on the pgp's.
I sure don't love systems with high pressure losses in the field plumbing. I can get surprised by 'extra' well capacity, when the time isn't there to spend hours on a flow test, and I instead follow the lead of the existing zone plumbing.

One renovation turned into a Jekyll and Hyde system, as the well had more flow than existing zones were using, and I had to bring up the pressure switch settings to prevent cycling, so the zone nearest the supply runs like gangbusters at 60+ psi, and the one fed by 200 feet of one-inch poly is closer to 30 psi.
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  #22  
Old 06-21-2013, 10:58 AM
Kiril Kiril is offline
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Originally Posted by Wet_Boots View Post
One renovation turned into a Jekyll and Hyde system
Ahhhhhh, the booty special.
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  #23  
Old 06-21-2013, 08:22 PM
HunterTekGeek HunterTekGeek is offline
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PGP Seals and More

The PGP rotors are built to withstand operating pressure of up to 100 PSI without blowing apart, but there can be other external factors that create problems. For instance, if there are slopes or even slight elevation changes, then the lateral pipes drain out. So when the zone first starts thereís an excessive amount of water flowing through the empty pipes at a high velocity. When that water stops, sometimes it can blow off nozzle turrets or break body caps. To help prevent the low head drainage and start up damage, install drain check valves in the PGPs which hold back about 3-4í of elevation change, or better yet, install the I-20 that comes with a stronger spring and check valve that holds back 10í of elevation change.

As for the nozzles themselves, they are designed to operate most efficiently at 40-50 PSI. If the pressure is higher, the water droplets are smaller and more misting and drifting will occur. And, if the nozzles are diffused to reduce the radius, that too may cause additional misting. How do you accurately check the dynamic pressure? Use a pitot tube shown below. Simply place the very small tube directly into the center hole of the nozzle and read the gauge. More importantly how do you reduce the pressure if itís too high? One possible way is to turn down the flow control on the valve, then recheck the pressure.

The leaking may be from caused from an old, deteriorated, hardened riser seal. That seal not only seals on the outside of riser that pops up, but it also seals against the inside of the body. Once the seal is old, it can shrink in size and harden, then it no longer is flexible enough to seal on the body, so water leaks below the cap. To return the sprinkler to nearly new condition, simply replace the riser seal and reinstall the head. For more information see the information below.

http://www.hunterindustries.com/supp...-or-repair-fix
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  #24  
Old 06-21-2013, 08:29 PM
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Quote:
Originally Posted by HunterTekGeek View Post
To return the sprinkler to nearly new condition, simply replace the riser seal and reinstall the head.
Bull crap, this has been going on for years. It's not that simple to replace the riser seal, it's easier to replace the head with a 5004.
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  #25  
Old 06-21-2013, 09:48 PM
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Mike Leary Mike Leary is online now
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If everyone would use 6" heads and learn to install them to the proper grade, I'd bet we'd see fewer problems with wiper seals.
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  #26  
Old 06-21-2013, 09:52 PM
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irritation irritation is offline
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Originally Posted by Mike Leary View Post
If everyone would use 6" heads and learn to install them to the proper grade, I'd bet we'd see fewer problems with wiper seals.
That would make no difference with PGP's. I've seen them leak no matter the circumstances.
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  #27  
Old 06-21-2013, 09:59 PM
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Mike Leary Mike Leary is online now
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Quote:
Originally Posted by irritation View Post
That would make no difference with PGP's. I've seen them leak no matter the circumstances.
I know Boots thinks the guts are the same, but in 12 years, I've had zero problems with I-20 stainless 6".
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  #28  
Old 06-21-2013, 10:05 PM
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Hunter always had a burden with the PGP seals. The head could use such tiny nozzles that flow-by had to be equally tiny. And of course, the best wiper seal is patented by their competitor.
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  #29  
Old 06-21-2013, 10:16 PM
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irritation irritation is offline
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I used them for years with no problems. I think the rubber or plastic or both was changed at some point and ruined the head.
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  #30  
Old 06-21-2013, 10:29 PM
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Wet_Boots Wet_Boots is online now
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the seals were a headache through most of the PGP's first few years - not until the later 1980's did they come up with something workable
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