... : brass alloy, chrome plating 3.DN15(1/2")DN20(3/4" fire sprinkler different type: ... 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) flux coefficient: 80,115(6) large ... is,DN 15mm, connect thread R1/2”, flow coefficient 80, rated W.P 1.2Mpa DN 20mm, connect thread ...