Abstract: The present invention relates to a device for periodically rinsing a water cock countersunk in the ground. A drainpipe is connected between the water cock and a closing member of an extension piece. The drainpipe includes a valve body which is opened by the water pressure prevailing in the extension pipe when the water cock is initially opened. After a predetermined period of time the valve body is closed. Thus, the present invention ensures that after the water cock is opened dirt is flushed away through the drainpipe which is subsequently automatically closed after a predetermined time. After the drainpipe is closed, a valve member connected to the extension pipe can be opened and only pure water will be supplied.

Abstract: A check valve having a predominantly cylindrical housing, a sealing diaphragm comprising a thin, tubular slip and at one extremity a radially outwardly extending fastening flange, said flange being clamped between an uninterrupted inner shoulder in the housing and an annular locking member of a synthetic resin, having an outer surface being at least partly tapering, said locking member being enclosed between the fastening flange and an inwardly projecting protuberance of the housing, and a rotation symmetrical closing member being axially displaceable between a closing position sealing on the slip and an opened position away from said slip.When assembling the component parts of this check valve the diaphragm is first installed and thereafter the locking member is forced in position by an axial movement only.