Sewer drain trap primer valve

A sewer drain trap primer valve comprising

• a case defining a volume, said case having an upper end and a lower end, said upper end defining an inlet orifice for communication of the volume with a source of domestic water, said lower end defining an outlet orifice for communication of the volume with a sewer drain trap,
• a flexible diaphragm separating said volume into an upper, water chamber and a lower, sealed, air chamber,
• a conduit member defining a conduit connecting said upper, water chamber with said outlet orifice, said conduit member defining a first valve seat,
• a valve assembly comprising a float element, with a first valve element mounted thereupon, said float element having a continuous outermost surface of a constant diameter and being adapted for movement between a first position and a second position in response to differential of pressure between said inlet and said water chamber,
• in said first position, said first valve element being in engagement with said first valve seal for restricting flow of water from said water chamber into said conduit, and
• in said second position, said first valve element being spaced from engagement with said first valve seat to permit flow of water from said water chamber into said conduit, and
• a check valve adapted to permit flow of water in a direction from said inlet toward said water chamber and to restrict flow of water in a direction from said water chamber toward said inlet, said check valve comprising a check valve element mounted upon said float element, said case including a radially inwardly extending check valve seat, and said check valve element defining a check surface disposed for sealing engagement with said radially inwardly extending check valve seat when said first valve element mounted upon said float element is in a second position, said check surface being spaced from engagement with said radially inwardly extending check valve seat when said first valve element mounted upon said float element is in a first position, said check valve element comprising a resilient member extending radially from said outermost continuous surface of said float element.