Non-return valves are check valves that allows flow in one direction only. They can be found on scour valve outlet pipes, fitted to prevent backflow into the main pipe. NRVs are usually fitted to pump discharges, after the discharge isolation valve. The main application is in reservoir inlet pipes, which prevents the loss of stored water in the reservoir. The styles range from swing type to nozzle type and from flanged bodies to wafers. This valve is also used as a weak link to prevent damage to the inlet pipe work cast into the reservoir.
Non rotating air tube system optimizes chuck performance by completely eliminating air tube vibration. The HST chucks are also available with a patented non-rotating air tube assembly, which eliminates the vibration typically associated with rotating air tube designs at very high spindle speeds. It is also available in 3 & 4 inch non rotating air tube diaphragm chuck. It reduces vibration due to an unbalanced air hose.