SAFETY VALVE DEVICE FOR GAS CIRCUIT

摘要

PURPOSE:To detect abnormality over the entire area of a downstream side circuit and to interrupt a gas circuit by providing a main valve which closes corresponding to the output condition of a means for detecting abnormality in the downstream side circuit. CONSTITUTION:When there is no abnormality in the downstream of a safety valve device under normal use condition, pressure at the downstream side of a main valve 1 is higher than a predetermined level, and thereby a predetermined output is produced in a detecting means C thus maintaining open-valve condition of the main valve 1. Upon occurrence of abnormality at the downstream side, pressure at the downstream side drops below a predetermined level to eliminate output from the detecting means C so as to eliminate open- valve holding force of an open-valve holding means 3 thus reseting the main valve 1 to closed condition. Since pressure at the downstream side drops below a setting level when abnormality occurs at any position in the downstream side piping, the main valve 1 closes regardless of the occurring position of abnormality.