valve is open or closed. They should be readily accessible for maintenance and oriented so that their handles are easy to operate. Seacocks and through-hulls are made of bronze or glass reinforced plastic. Both can be used successfully for toilet intake or overboard discharge lines. Bronze seacocks and both bronze and glass reinforced plastic ball valves may be used for toilet in take or overboard discharge lines. It’s generally a good idea, however, to fit plastic valves on reinforced plastic through-hulls. Either glass reinforced plastic or bronze valves may be fitted to a bronze through-hull. The use of gate valves, which are made of brass, should be avoided because they corrode rapidly and their stems tend to break. PumpsEnsure that all pumps are suited for use in sewage systems. Capacity is key to pump performance. Pumps may be made of bronze, aluminum or plastic. Bronze is frequently used in constructing rugged, high capacity pumps, while aluminum pumps are typically less expensive, but prone to corrosion. Plastic pumps are lighter and corrosion resistant, but also more likely to leak since some plastics can deform over time. Diaphragm pumpsSometimes used to flush the toilet, diaphragm pumps are frequently used to pump out the holding tank. They may be manual or electric. Advantages: Pass solids more readily than do piston pumps. Can be run dry without damage. Simpler design makes them less troublesome than piston pumps. Disadvantages: None in waste system applications.Macerator pumps Macerator pumps used to break up and pump wastes from many holding tanks. They may be installed inside or on top of the tank, or mounted separately. A macerator pump is not a Type I or II MSD; it does not treat sewage to reduce bacteria content. Advantages: Break up solid wastes, thereby minimizing the likelihood of clogged piping downstream. When installed at the toilet, typically require...
