空气关闭阀 air shut-off valve ; off valve

密闭排气阀 closed exhaust valve

闭气阀 gas check valve ; gas blanketing check valve

煤气关闭阀 gas shutoff

天然气关闭阀 natural gas shutoff

空气封闭阀 air shut-off valve

关闭空气入釜阀 Air to Cylinder Valve