Are the PVC Swing Check Valves Sch.40 or Sch.80?

 
    They are neither “Sch.40” & Sch.80”, PVC Swing Check valves, like PVC Ball Valves are rated by pressure / temperature not by schedule.  

    The “Sch.40” & Sch.80” terms refer to pipe and PVC fitting wall thickness only, not valve wall thickness; the higher the Schedule number, the thicker the pipe wall. Equally important, the inside diameter gets smaller as wall thickness increases, while the outside diameter remains the same.

    That’s why a “Sch.80 valve” can be installed onto a Schedule 40 piece of pipe, and vice-versa.

    Since Schedule 40 and 80 are terms that describe pipe and fittings, why do some valve suppliers use them to describe their valves?

    Unfortunately, some manufacturers and distributors describe PVC valves using these pipe-descriptive terms causing a great deal of confusion. It is important to remember that, all valves are rated by pressure, not wall thickness (schedule). White PVC resin was typically used to make Schedule 40 PVC pipe and fittings and Gray PVC resin was normally used to make Schedule 80 PVC pipe and fittings. However today both Schedule 40 and 80 PVC pipe and fittings are manufactuered in both colors of resin and color no-longer is an indication of the schedule of the fittings or pipe.