ballardFan
New Member
I have a water line that is approximately 7500 feet long from the meter to my property. The meter is a 1.5" service. My line is 2" and is a mixture of 5400 ft HDPE, a small bit of sch 40, and about 2000ft sch 80 PVC at different points.
Pressure at the meter is about 100 PSI.
Over the 7500 ft distance the line descends from 468 ft to 30 ft final elevation which adds ~202 PSI to the starting pressure. I know there are other factors like friction loss to factor in but either way the pressure on this line is huge so I have a lot of equipment to deal with it.
I have multipe PRVs on the line now.
PRV 1: Right after the meter to drop the start pressure to 50 PSI before it runs down the slope.
PRV 2: 2500 ft distance after a drop of about 90 ft in elevation. It again drops back to ~50PSI.
Another 3500 ft down the line I have a service hose bib and checked the pressure and it is 120 PSI. The increase in pressure at this bib is from the elevation drop and all tracks about right.
PRV 3 is about 100 ft from my first house tap at the 30 ft elevation. I am estimating input pressure is around 180PSI (120 psi measured plus elevation drop adding about 61 PSI). I don't have a great way to measure input pressure.
I just replaced PRV#3 with a new Zurn Wilkins 600 XL2 which has the integrated check valve. As far as pressure control it is holding perfect for my whole property at 50 psi after this PRV.
My Issue: I am having a problem since I replaced PRV3 where when I have all flow shut off at my house it will blow out the line back up the hill.
It did not occur before i replaced the PRV. It will not occur as long as I have some flow going either.
My understanding is the spring loaded nature of the PRV is basically causing a water hammer to run "back" up the pipe. I assume this higher quality PRV is hitting the line harder (e.g. the spring is reacting faster then the old one did).
Question:
Is my assessment accurate? What should I do? Add another intermediate (4th) PRV? Add a mega hammer arrestor or a series of them like these: Zurn Wilkins Z1700-600 #600 Shoktrol Water Hammer Arrestor?
Pressure at the meter is about 100 PSI.
Over the 7500 ft distance the line descends from 468 ft to 30 ft final elevation which adds ~202 PSI to the starting pressure. I know there are other factors like friction loss to factor in but either way the pressure on this line is huge so I have a lot of equipment to deal with it.
I have multipe PRVs on the line now.
PRV 1: Right after the meter to drop the start pressure to 50 PSI before it runs down the slope.
PRV 2: 2500 ft distance after a drop of about 90 ft in elevation. It again drops back to ~50PSI.
Another 3500 ft down the line I have a service hose bib and checked the pressure and it is 120 PSI. The increase in pressure at this bib is from the elevation drop and all tracks about right.
PRV 3 is about 100 ft from my first house tap at the 30 ft elevation. I am estimating input pressure is around 180PSI (120 psi measured plus elevation drop adding about 61 PSI). I don't have a great way to measure input pressure.
I just replaced PRV#3 with a new Zurn Wilkins 600 XL2 which has the integrated check valve. As far as pressure control it is holding perfect for my whole property at 50 psi after this PRV.
My Issue: I am having a problem since I replaced PRV3 where when I have all flow shut off at my house it will blow out the line back up the hill.
It did not occur before i replaced the PRV. It will not occur as long as I have some flow going either.
My understanding is the spring loaded nature of the PRV is basically causing a water hammer to run "back" up the pipe. I assume this higher quality PRV is hitting the line harder (e.g. the spring is reacting faster then the old one did).
Question:
Is my assessment accurate? What should I do? Add another intermediate (4th) PRV? Add a mega hammer arrestor or a series of them like these: Zurn Wilkins Z1700-600 #600 Shoktrol Water Hammer Arrestor?