PURPOSE: To keep off any leakage of a refrigerant by installing a body provided with a flow port and a socket and another body provided with an insert part being inserted into this socket and vice versa and a mounting port and a flow passage sliding a slide valve and interconnecting both these flow and mounting ports all in a slide shaft.

CONSTITUTION: A slide valve 14 is formed in a body 15 provided with a flow port 12 and a socket 11 so as to close an opening 13 of the socket 11 with a spring 16. Likewise, a slide shaft 21, a mounting port 24, a projecting valve 23 opening or closing an opening 27 and a flow passage 25 are all installed in a body 22 provided with an insert part 26 which is inserted into the socket 11, and a slide shaft 21 is slid as in an arrow C, then a slide valve 14 is slid by projection of the projecting valve 23. With this operation, the flow passage 25 of the slide shaft 21 has the flow port 12 and the mounting port 24 interconnected with each other. Consequently, fluid resistance of a refrigerant becomes smaller as compared with the conventional one, thus stable operation is performable and, what is more, closing and opening operations for flowing of the refrigerant are ensurable, making any leakage of the refrigerant preventable.