air reducing valve Pressure classification Entry pressure(P1) Exit pressure(P1) A 3.0 1.0~0.7 B 3.0 0.7~0.2 C 1.0 0.4~0.05 Nominal diameter Structure dimension Male thread connect size weight entry exit DN1 DN2 L H h D1 D2 D3 L1 L2 D4 D5 D6 L3 L4 kg 15 20 140 312 103 M36*2 33 22 22 5 M39*2 36 25 23 5 6.57 20 25 229 390 123 M39*2 36 25 23 5 M48*2 45 32 26 6 22.3 25 32 229 390 123 M48*2 45 32 26 6 M56*2 53 38 28 6 27.3