We have a 6-story condo building. It's an NFPA 13 system on the first floor, and NFPA 13D with PVC piping above.
Over the years this building has had leaking sprinklers. The last two leaks were within a week of each other, one in the second floor laundry room and one in the large lobby sitting area.
The leaks have been found by residents; no waterflow alarms. The sprinkler company who put it in is still doing yearly testing and maintenance. The fire units for these two events found the pressures in the stairwells at 150 psi. The jockey pump turns on at 120 and off at 133.
The sprinkler company says the sprinklers in the PVC piping are leaking at the fitting behind the sprinkler and not the sprinkler itself.
The connection between the sprinkler and the fitting was either cross threaded or over torqued.
Last week I found the gauge on the 6th floor reading 110 psi and the 1st floor at 130 psi.
Can pressures of 150 psi plus at extended periods of time cause the leaking?
The pipe is rated to 175 psi. The building was built in 1989.
And for my own knowledge-the pressure in systems of this type are this high for what reason?
We are told the pressures are typical. Thanks in advance.
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