... (80) 2.chrome alloy fire sprinkler 3.1/2" , 3/4" with 57,68,79 or 93 4.standard response 1/2" fire sprinkler(1) rated ... working pressure: 12 bars(1.2Mpa)(2) airproof test pressure: 24bars(2.4Mpa)(3) strength test ... pressure: 30bars(3Mpa)(4) thread: 1/2”,3/4”(5 ...