PVC Swing Check Valve
The pvc swing pvc swing check valve of the present invention is directed toward applications in pipe lines in which low back pressures are experienced. Specifically, swimming pools, spas and tanks have plumbing structures which often require pvc swing check valves to prevent back flow from filtration systems located at a higher elevation than the motor and pump used to force fluid through the system. Similar pvc swing check valves may also be used on manifold piping systems where two or more pumps may operate independently of each other and/or at different time intervals. Such pvc swing check valves may also be used directly in conjunction with pumps wherein the pvc swing check valve maintains fluid in the housing for priming purposes. A nut member extends around the insert member and engages the first and second pipe sections whereby the front and rear surfaces of the insert member are held in contact with the first and second sealing surfaces of the first and second pipe sections. The nut includes interior surfaces defining first, second and third interior circumferences of the nut wherein a transition between the first and second circumferences defines a ledge for engaging a flange on the first pipe section, and the third circumference includes a threaded portion for engaging a threaded portion of the second pipe section. Thus, as the nut is threaded onto the second pipe section, the ledge defined between the first and second circumferences will draw the flange on the first pipe section axially toward the second pipe section. Each of the pipe sections 12, 14 further include an outer flange 44, 46 extending radially outwardly from respective outer walls 22, 30. A radially outer surface 48 of the flange 44 defines a maximum circumference of the first pipe section 12. The second pipe section flange 46 includes a substantially smooth annular surface 50 adjacent to the first end 24 and a threaded portion 52 which defines a maximum circumference of the pipe section 14 greater than the circumference of the annular portion 50. The insert member includes a main spoke member extending diametrically across the aperture of the diaphragm member and a plurality of additional spoke members are provided extending diametrically across the aperture and intersecting the main spoke member. Additional spoke members 90 are provided extending diametrically across the aperture in the insert member 58 and intersecting the main spoke member 74. The additional spoke members 90 limit the movement of the diaphragm flap portions 78, 80 toward the rear face 66 of the insert member 58 to thereby facilitate seating of the flap portions 78, 80 on the seating surface 70 defining a closed position for the pvc swing check valve assembly 10.