RELATIVE PRESSURE CONTROL SYSTEM AND RELATIVE FLOW RATE CONTROL SYSTEM

摘要

The invention provides a relative pressure control system of simple construction capable of accurately adjusting partial pressure ratio for working gas and reliably removing the working gas from a working gas supply pipeline in an emergency. It comprises a plurality of normally open type air-operated valves (8) connected to a working gas supply pipeline supplied with working gas, pressure sensors (3) individually connected in series with the air-operated valves (8) for detecting the pressure delivered from the air-operated valve, a controller (25) for controlling a operating pressure for the air-operated valve (8) on the basis of the pressure detected by the pressure sensor (3), a hard interlock solenoid valve (59) for associating the plurality of air-operated valves (8) such that normally at least one valve is opened, the arrangement being such that of the plurality of air-operated valves (8), a specified air-operated valve (8) has its degree of opening adjusted so as to deliver the working gas at a predetermined partial pressure ratio.