Attention: TDR Forum Junkies 
This is for the waterguys/engineers. I'm project manager on a shared trench, gas/water replacement project. My background is in the natural gas biz hence my ignorance.
The water contractor is having problems getting a test on the app. 3500' of 12" ductile and 1500' of 8" ductile we've installed this summer. Take it to 200psi, next morning it's down to 100psi. Looks like a leak to me. We tested our 8" PE gas at 1. 5 times maop (95psig actually), 24hrs later, no drop. No leak. Simple.
Water guy keeps saying it's air in the lines and after it's flushed out, no problem. But he can't explain how if the air (that is likely still in since we can't flush one hydrant) is compressed to 200psi, it can cause a drop without a leak, just claims it does. I can see it mixing with the water, makes it look like milk. But if no leak, why the pressure drop? I'm thinking he has a gasket rolled a bit in a joint and once the pressure drops, it quits leaking.
?????????????
Thanks, RJR
The water contractor is having problems getting a test on the app. 3500' of 12" ductile and 1500' of 8" ductile we've installed this summer. Take it to 200psi, next morning it's down to 100psi. Looks like a leak to me. We tested our 8" PE gas at 1. 5 times maop (95psig actually), 24hrs later, no drop. No leak. Simple.
Water guy keeps saying it's air in the lines and after it's flushed out, no problem. But he can't explain how if the air (that is likely still in since we can't flush one hydrant) is compressed to 200psi, it can cause a drop without a leak, just claims it does. I can see it mixing with the water, makes it look like milk. But if no leak, why the pressure drop? I'm thinking he has a gasket rolled a bit in a joint and once the pressure drops, it quits leaking.
?????????????
Thanks, RJR
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