BALL CHECK VALVE AND MANHOLE PUMP UNIT USING IT

摘要

PROBLEM TO BE SOLVED: To provide a ball check valve capable of integrally forming a main body, disposing one air vent hole in a suitable position in consideration of workability, and coping with various kinds of connecting methods by common products. SOLUTION: In this check valve, a ball 10 movably provided in a body 1 is seated on a primary side seated part 16 to prevent reverse flow of a fluid. An insert cylinder 13 is inserted in the primary side of the body 1, and an air vent hole 14 formed in the outer peripheral surface of the insert cylinder 13 is opened in the outer peripheral surface of the body 1.