I'm installing a tankless water heater at the opposite side of my house
from the natural gas meter. I have a dedicated pipe-run going directly
from the meter to the appliance. My primary problem is getting the
approximately 65 feet of new black pipe to COMPLETELY hold the test
pressure. All the inspector cares about is 15 psi for 10 minutes, but
this is my family's house! More details are below.
Sun at 4pm - 15 psi
Wed at 4pm - 15 psi
Thurs at 9pm - 13 psi
Fri at 9pm - 12 psi
I'm guessing the delay in the leak was caused by the extra time needed
to force the pipe dope out of the threaded connection. Once the seal
finally broke, I'm guessing the leak rate will be more constant until
that point when the operating pressure gets down to the 1-2 psi range.
Then the leak rate would slow.
Bottom line, I suspect I have not totally tightened a jont well enough
and that is the source of leak. I started this job by using Harvey's
Pipe Thread Compound, then I started using Rectorseal on the last
couple joints. I'm beginning to wonder if I should have used Harvey's
TFE past since that stuff does not appear to be nearly as runny as the
other two products.
Anyway, I'm interested in hearing about similar installation
experiences, and I'm always open to suggestions regarding installation,
pipe dope, pressure testing, etc. Thanks