PURPOSE: To pull a piston packing out of a cylindrical housing by fixing the piston packing onto an insertion member which is detachably coupled to the cylindrical housing.

CONSTITUTION: An insertion member 48 is removed out of a cylindrical housing 14 when repaired and maintained. Since a piston packing 58 is fixed onto the insertion member 48, and a discharge valve 60 is also interposed in the inside of the insertion member 48, the piston packing 58 and a discharge valve 60 are also taken out of the cylindrical housing 14 as the insertion member 48 is taken out of the cylindrical housing 14. Meanwhile, a suction valve 26 is pulled out of a reciprocating member 18 from the tip end of the reciprocating member 15 in such a way as to be taken out of the cylindrical housing 14 from the tip end of the cylindrical housing 14.