SEAL-GAS VALVE DEVICE

摘要

During the pumping of corrosive gases, it is advantageous to admit a seal gas to endangered pumping chambers at a lower flow rate and a higher pressure than the corrosive gases. Inert gas from a supply (3) has its pressure reduced by a pressure reducer (6). An on/off valve (7) controls a flow of the inert gas through a flow restriction (8) which restricts the flow of inert gas to appropriate sealing gas rates at an outlet (4). After pumping the corrosive gas, a control valve (12) in a bypass line (11) causes the inert gas to be supplied to the outlet (4) at a higher flow rate for purging the pump.