CHECK VALVE AND MANUFACTURING METHOD THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a pipe built-in type check valve of a welding structure, having excellent reliability without increase in number of parts and external leak and reducing the occurrence of defective in manufacture. SOLUTION: A check valve assembly 12 including a valve seat member 14 and a valve element 17 is inserted in a pipe body 11, and the valve seat member 14 is fixed to the pipe body 11 by seam welding (a seam welding part 18). COPYRIGHT: (C)2005,JPO&NCIPI