... alloy, chrome plating 3.DN15(1/2")DN20(3/4" fire sprinkler different type: pendant type, upright type, ordinary type, sidewall ... horizontal type. Concealed typespecification:(1) rated working pressure: 12 bars(1.2Mpa)(2) airproof test pressure ... is,DN 15mm, connect thread R1/2”, flow coefficient 80, rated W.P 1.2Mpa DN 20mm, connect thread R3/4 ...