Incorrect check valve selection can aggravate surge and water-hammer in pipeline systems, resulting in what is known as “Check Valve Slam” causing transients which could exceed the pipeline’s working pressure by up to five times. Check valves can also be one of the biggest contributors to head loss within a pipeline, which in turn increases power consumption. Vent-O-Mat’s range of nozzle check valves addresses both these concerns by providing a non-slam valve with a very low pressure loss.
The valve utilises a ring-shaped disc as the closing member. Rapid slam-free closure is achieved utilising friction free helical springs and radial guides. Annular ring type nozzle check valves outperform center shaft nozzle designs (mushroom type) in respect of dynamic and head loss performance because of the low mass of the moving parts (ring shaped disc) and the superior pressure recovery capabilities inherent in the two-port annulus configuration
- Non-slam closure – the valve responds rapidly to changes in velocity that the disc is at the point of closure before reverse flow occurs
- Low pressure loss – in the open position the annular disc forms two flow paths which increases the volume of flow through the valve
- Short closure time – the short stroke length reduces closure time
- Friction free opening and closing – helical springs and radial guides allow the disc to move from the open to closed position with limited resistance
- Tight shut off – achieved by metal – to – metal sealing
- No scheduled maintenance