METHOD FOR FORMING VACUUM CHAMBER IN THE CONTROL VALVE

摘要

PURPOSE: A method for forming a vacuum chamber of a control valve is provided to minimize residual stress and thermal deformation at a welded part by spot-welding the flange units of upper and lower housings and a diaphragm. CONSTITUTION: A method for forming a vacuum chamber of a control valve is as follows. An upper housing(40) is placed in a receiving part(22) of a lower electrode jig(20) at a vacuum chamber(50). An upper electrode jig(10) is descended. Flange units(42,32) of the upper and lower housings are spot-welded by applying specific voltage to the upper and lower electrode jigs. The upper and lower housings are put into an inspection chamber. Helium is supplied to the inside the inspection chamber. The vacuum states of the upper and lower housings are inspected.