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Pneumatic emergency shut-off valve (marine) QDQ421 F-25/40

Features

1. Applicable to gas pipelines for safety protection. In the delivery state, the valve is normally closed. When working, the gas source acts on the cylinder and the valve opens.
2. Adopting the principle of check valve, it can only be cut off in one dire

Technical Parameters


Technical parameters:   


Nominal pressure Mpa 2.5 4.0
Shell test pressure Mpa 3.75 6.0
Sealing test pressure Mpa 2.75 4.4
Applicable temperature -40℃-+50℃
Applicable media Liquefied petroleum gas, natural gas, liquid ammonia, etc.
Flange Standard GB/T9113__2000
Manufacturing standards JB/T9094-1999
Emergency cut-off time ≤10-30S
Melting temperature of fusible plug 75±5℃
Cylinder applicable medium Compressed air, nitrogen
Air source pressure Mpa 0.3-0.6

Main parts materials

Valve body Valve stem Valve disc spring Gasket cylinder Sealing ring
WCB 20Cr13 20Cr13 50CrVA,1Cr18Ni9 PTFE 20# NBR

Station pneumatic emergency shut-off valve QDQ421F nominal pressure PN2.5Mpa   overall dimensions and connection dimensions

DN L D Dl D2 D3 Convex D4 concave b f Z-φd H1 H2
150 444 300 250 211 203 204 28 4.5 8-φ26 730 353
200 533 360 310 274 259 260 30 4.5 12-φ26 850 410
250 622 425 370 330 312 313 32 4.5 12-φ30 899 441