SAFETY SHUT-OFF VALVE.

摘要

PCT No. PCT/JP81/00351 Sec. 371 Date Mar. 15, 1982 Sec. 102(e) Date Mar. 15, 1982 PCT Filed Nov. 20, 1981 PCT Pub. No. WO82/01756 PCT Pub. Date May 27, 1982.A safety shut-off valve opening a flow path between the primary and secondary sides in case of usual operation, while shutting off the aforesaid path in response to an emergency shut-off signal, and particularly such safety shut-off valve cannot be reset unitl it is confirmed that there is no more leakage of gas on the secondary side of the shut-off valve after the shut-off action was once effected, thereby to attaining a very high safeness.