Abstract: A disconnect unit for the isolation of the aqueous contents of a swimming pool from pump lines running into said pool which permits contained water to be blown clear of said pump lines without need to remove any substantial quantities of water from the pool. The unit comprises a pool inlet fitting having a check valve permanently mounted therein and adapted to have inserted within the check valve at its distal end a compressed air nipple and at its proximal end frictionally and permanently embedded into the wall a blocking membrane for the inlet fitting member. The device functions by the first insertion of the compressed air nipple 1 into the check valve 2 and the locking of the shoulders of the two members together. The air line to the pump is then blown clear of water.