Hi, I recently had a new run of black pipe installed from the meter to where the new boiler will be installed. They pressure tested the line to 25psi and 5 days later it dropped to 5psi and failed inspection. The plumber returned, pressurized the line to 100psi and found a leak at a joint. The joint was fixed and the line was pressurized again to 26psi. 6 days later, today actually, the gauge now reads 14 psi. The re-inspection is scheduled for this coming Wed. but it looks like it may fail again.
Is there a certain amount of time or a minimum amount of pressure that the pipe has to hold indefinitely?