Abstract: A pump has a solenoid with an armature directly connected to an elastomeric diaphragm. Upon flow of half wave rectified ac current in the solenoid, the armature oscillates the diaphragm. A valve holder has duck-bill type inlet and outlet valves received therein. The valve holder is retained between a valve body and an armature guide member by fastening means which simultaneously effect sealing of the diaphragm rim and the rims of the duck-bill valves. The armature has portions thereof directly engaging a detent recess formed in a central buffer portion of the diaphragm.