Profile: Rotech Pumps & Systems Inc. is a distributor of industrial pumps and mechanical seals. DNJ series end suction close coupled centrifugal pumps are close coupled with standard JM solid shaft motors. Close coupled centrifugal pumps are designed solely for applications in medium duty service, in heating and air conditioning, booster and general circulating. End suction pumps are available in cast iron bronze fitted and all iron Materials of construction (MOC) with type 21 mechanical seals. Ball check valve has a simple yet robust design. When the pump starts, it allows free flow of the liquid and its innovative design comprises of a rubber ball that prevents back flow of liquid. This spherical rubber ball seals perfectly against the valve seat to ensure leak proof sealing. Ball check valves are designed to handle high pressure applications wherein reverse flow / leakage must be kept to minimum. They are ideal for slurries, sewage, viscous, erosive & corrosive liquids.