Device for temporarily rinsing a water cock countersunk in the ground

A drain valve for use with a water cock countersunk into the ground surface and including an extension pipe piece with a closing member being disposed above the ground surface, said water cock being in fluid communication with said extension pipe piece and said closing member comprising:

• a drain pipe device operatively connected between the water cock and the closing member positioned in the extension pipe piece;
• a valve body slidable disposed adjacent to said drain pipe device to selectively permit the fluid communication between said extension pipe piece and said drain pipe device;
• biasing means for normally biasing said valve body into an open position for normally permitting the fluid communication between said extension pipe piece and said drain pipe device during initial opening of said water cock for permitting rinsing of impurities from the water cock prior to the opening of said closure member;
• and
• delay closing means actuated by fluid pressure within said extension pipe piece for closing said valve body to prevent communication between said extension pipe piece and said drain pipe device after the expiration of a predetermined time period.