A. There are many qualities of plastics, and you can be assured that we only ship top-of-the line plastics. Having said that, these are made out of plastic and this material has pro's and con's. These will degrade in sunlight over time, unlike brass valves. These, under normal wear and tear, in most situations, "should" last at least 2-7 years. Quality brass valves will last longer under most conditions (not in aggressive water conditions). For sewage, ponds, fountains and sump pump applications, we believe that our above PVC swing checks are the best product for the conditions that these are exposed to.