Hello. Hope to get some new brains on this one

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P_lumber

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Hello, didn't choose plumbing.... Plumbing chose me. It's a love hate, that's my introduction. If you need to know more feel free to ask.


Got a system in the ground and we've been having issues for months. Between the pipe ordered, pipe received and system that it's for is all wrong and I already understand that. Owners and engineers get what they want. I've fought my fight. And lost.

Pipe is underground, sch. 80 pvc. Ranges from 1.5" to 4". Have a supply and a return. Had multiple leaks and all leaks have been fixed to the best of our knowledge. (All leaks were 3 and 4") Pipes are capped in crawl space and are isolated out from each other.

Filled the RETURN up to bldg pressure at 64lbs. No issues at all, bled air and filled within 15 minutes.

Go to fill the supply and after 10 minutes we had no pressure. My first thought is another break, guy calls me over and we have built 2 lbs. call the horses off we aren't going to break ground on yet another hole. Not yet. Let it build to about 10 lbs after nearly an hour. Valve open can hear it burping. Swap sides to fill from. Possibly air locked? Nope, same story. Took me 4 hours to build 42 lbs. So I think I know what you're gonna tell me now. You've got a good leak and are just putting in more than you're losing. That's also incorrect. Pipe holds pressure at 42. There are no PRVs or anything on the system. at least not on what I'm testing those have also been isolated at the manifolds. No clogs in the hose, no clogs on the aerator. I'm baffled. Maybe I'm worn out with the system. Need some advice.
 
Possibly jet the line?? But if something was in the line it would still build pressure around whatever is in the line.....
 
need some clarification.
What is the system for? Domestic water?
Supply and return. What is the return for? HOT water :confused:
Is this a new system not yet put into service or existing and previously in use?


Pipe is underground, sch. 80 pvc. Ranges from 1.5" to 4". Have a supply and a return. Had multiple leaks and all leaks have been fixed to the best of our knowledge. (All leaks were 3 and 4") Pipes are capped in crawl space and are isolated out from each other. Not exactly sure what you mean here


Filled the RETURN up to bldg pressure at 64lbs. No issues at all, bled air and filled within 15 minutes.

Go to fill the supply and after 10 minutes we had no pressure. My first thought is another break, guy calls me over and we have built 2 lbs. call the horses off we aren't going to break ground on yet another hole. Not yet. Let it build to about 10 lbs after nearly an hour. Valve open can hear it burping. Swap sides to fill from. Possibly air locked? Nope, same story. Took me 4 hours to build 42 lbs. So I think I know what you're gonna tell me now. You've got a good leak and are just putting in more than you're losing. That's also incorrect. Pipe holds pressure at 42. There are no PRVs or anything on the system. at least not on what I'm testing those have also been isolated at the manifolds. No clogs in the hose, no clogs on the aerator. I'm baffled. Maybe I'm worn out with the system. Need some advice.

I re-read this again.
You are filling a very large system with water.
Does it max out at 42 psi and holds at 42 with no additional water added?
Must be a very large system to take 4hrs to fill.
Are you using available water pressure to fill the system or a pump.
water main pressures around here are between 80 & 150psi


I know the feeling of baffling jobs that boggle the mind. I use Google map sometimes to see the big picture sometimes from a birds eye view. This may not at all help but if you can make a schematic or basic layout drawing of system you are working on.
 
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Snowmelt system. At one point in time we had the system up in running with no issues at all. As soon as we took the heat off of the water is when leaks started to pop up. Expansion and contraction really did a number. All leaks have been fixed and thrust blocks are waiting to be poured. We have had so many issues with this I'm not going to rush it, I simply don't understand how I'm not able to build pressure on my main yet the main doesn't leak. I've swapped gauges, the gauges are all fine. I've got the prints, specs, submittels, got all of it but the brass tax is it's simply PVC pipe that can't build pressure and I have absolutely no clue why. The system itself is less than a year old.
 
I re-read this again.
You are filling a very large system with water.
Does it max out at 42 psi and holds at 42 with no additional water added?
Must be a very large system to take 4hrs to fill.
Are you using available water pressure to fill the system or a pump.
water main pressures around here are between 80 & 150psi


We are filling up from a mop sink in the building. Pressure from the city varies during the day. Generally around 70-85, got the PRV set at around 65. The systems is pretty large but the supply and return are the exact same size. Same fittings, same pipes. They run side by side and are damn near identical. We filled out return and bled of all the air and had the system at 64 lbs within 30 minutes, 15 or so. butthe supply is being difficult. I can get water/air from the opposite side from where I'm filling but it just won't build pressure. It's slowly building, when you take the water source away it maintains pressure. I can fill from point a, get water and air to come out from point b. I can do it either way. But regardless of what side I'm filling from it won't build pressure and it builds extremely slow. If I take my water source and test it I can build 65 or so lbs no problem.
 
Is your schedule 80 PVC or cpvc? On the 4" hot water systems I have installed we only use cpvc and cpvc glue because of the expanding and contracting. How hot does the water get? Could be popping glue joints one by one?

Are you getting all the air out for your test? Air compresses and water does not so air in a line being tested screws things up.
 
Hello, didn't choose plumbing.... Plumbing chose me. It's a love hate, that's my introduction. If you need to know more feel free to ask.


Got a system in the ground and we've been having issues for months. Between the pipe ordered, pipe received and system that it's for is all wrong and I already understand that. Owners and engineers get what they want. I've fought my fight. And lost.

Pipe is underground, sch. 80 pvc. Ranges from 1.5" to 4". Have a supply and a return. Had multiple leaks and all leaks have been fixed to the best of our knowledge. (All leaks were 3 and 4") Pipes are capped in crawl space and are isolated out from each other.

Filled the RETURN up to bldg pressure at 64lbs. No issues at all, bled air and filled within 15 minutes.

Go to fill the supply and after 10 minutes we had no pressure. My first thought is another break, guy calls me over and we have built 2 lbs. call the horses off we aren't going to break ground on yet another hole. Not yet. Let it build to about 10 lbs after nearly an hour. Valve open can hear it burping. Swap sides to fill from. Possibly air locked? Nope, same story. Took me 4 hours to build 42 lbs. So I think I know what you're gonna tell me now. You've got a good leak and are just putting in more than you're losing. That's also incorrect. Pipe holds pressure at 42. There are no PRVs or anything on the system. at least not on what I'm testing those have also been isolated at the manifolds. No clogs in the hose, no clogs on the aerator. I'm baffled. Maybe I'm worn out with the system. Need some advice.


the valves on your manifold are leaking thru.

disconnect, and hard cap your system
never test against valves, SOB's will bite you in the ass every time
 
The pipe is PVC. Shouldn't be but it is. It was a last minute change order to save a few bucks. I think we all know how that goes.....
All air is out, I appreciate all of the responses. But my biggest question is why can I not build pressure yet I can maintain pressure? For conversation sake let's say both supply and return are 100 ft each. (They are larger but let the systems for which its intended for and the type of pipe and all that go out the window) each reduce at the same spot, offset at the same spot, two pipes and they are the exact same. One builds pressure and maintains pressure. The other slowly build pressure, not nearly as much yet maintains the pressure we've put in. What would cause one pipe to not build its pressure?? Am I wrong that if something was in the line it would simply build pressure around the object in the line? That would only effect the rate of flow would it not??

And believe me brother I hate testing against valves, bastards always leak enough to give me a heart attack. But capping at the manifold isn't an option.
 
Should build at the same rate unless one has a lot of air in it.

Have you purged every bit of air out?

I had two identical 10" x 440' lines this month that I had to pump to 200 psi. One pumped up (after full of water) in about five minutes and the other took about 30 minutes and ten times the water through my pump. Reason was I had about 50 feet I could properly purge and it had air in the line. Made me think I had a leak.
 
I have seen rubber gaskets leak but maintain a pressure but you don't have them in your system.
 
Last I checked, pretty much all plumbing codes now require CPVC for any above-ground in-building applications now. If it serves hot water, then it must be CPVC because PVC can leach chemicals into the water at 70 degrees Celsius.

Even if it doesn't get that hot, the inspectors now want all inside pipes to be CPVC instead of PVC (unless you go with PEX, copper, or another approved material) so they don't have to try to figure out which lines are serving hot water.

So, that should probably all be replaced with CPVC.

Beyond that, I'm going to guess that Frodo is right because he's an expert and I'm not. I don't even know for sure what manifold valves are (although I have an idea).
 
The pipe is PVC. Shouldn't be but it is. It was a last minute change order to save a few bucks. I think we all know how that goes.....
All air is out, I appreciate all of the responses. But my biggest question is why can I not build pressure yet I can maintain pressure? For conversation sake let's say both supply and return are 100 ft each. (They are larger but let the systems for which its intended for and the type of pipe and all that go out the window) each reduce at the same spot, offset at the same spot, two pipes and they are the exact same. One builds pressure and maintains pressure. The other slowly build pressure, not nearly as much yet maintains the pressure we've put in. What would cause one pipe to not build its pressure?? Am I wrong that if something was in the line it would simply build pressure around the object in the line? That would only effect the rate of flow would it not??

And believe me brother I hate testing against valves, bastards always leak enough to give me a heart attack. But capping at the manifold isn't an option.

Hot water going through pvc. If so, I would say that's why it is leaking
 

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