Originally Posted by
Victor DaGraca
... with a lone sprinkler head. This unit was plumbed with Qest PB-2110.
As in poly bute?
Can't see a fitting at that galvanized elbow, is that PB coming out of the wall? If so, that PB is going to deflect downward under pressure from the sprinkler head operating, which could then crimp the PB, stopping the flow or at the very least cutting the flow to the sprinkler down dramatically.
Even the CPVC which is rated and approved for use with fire sprinkler systems needs to be secured within 6" of the elbow (for systems greater than 100 psi - 9" for systems 100 psi and less) for 3/4" pipe. PB is a lot more flexible than that CPVC.
Those CPVC systems are tested at 200 psi too.