For some applications, it is essential that non-return check valves are able to close rapidly to eliminate reverse flow. A quick reversing flow, as found in pump systems where one or more pumps feed into a high pressure main, requires that the check valve be very fast acting indeed if a large reverse flow is to be avoided. However, most check valves require all forward flow to cease completely before they can close. The resultant backflow and “water hammer” caused when the check valve does close has a far more serious implication. Under extreme conditions whole pipe and pump systems can be wrecked and even under less arduous conditions the cumulative effect of the shock waves can impair the proper working of the system and lead to an early breakdown with the subsequent high maintenance costs that this implies. Tilting Disk Check Valves guarantee fast closing functionalities and offer the solution to these problems
In collaboration with Northvale Korting we supply Tilting Disk Check Valves which have the following characteristics:
- Due to their design, tilting disc check valves open fully at water velocities as low as 0.6m/sec, thereby overcoming “disc flutter” commonly found in conventional tilting disc check valves and which leads to rapid wear of the shaft and bearings and the inevitable falling-off in efficiency.
- The disc is self-centring and sealing is effected by accurately turned and bevelled seats in the body and on the disc edge, giving tight shut-off at both high and low pressure differentials.
- The oblique seating angle, 15° on valves to 450mm diameter (10° for valves 500mm and above) gives a short angle of swing from fully open to close. The result is an extreme fast reaction time.
- The wafer body is compact, lightweight and economical especially where expensive raw materials are concerned.
- Small face-to-face dimensions enable tilting disc check valves to be fitted into the most cramped of piping layouts.
- The heavy stub shafts are positioned to give maximum strength with minimal clearance between the body and disc so that there is no unsupported length of shaft.
- All loads on the shaft are therefore carried in shear and not in a combination of bending and shear which can be the cause of so many failures in conventional valves used on steam and gas lines which are subject to rapid opening due to high velocity.
- Tilting disc check valves are designed to be fitted with auxiliary springs to accelerate the speed of closing. These springs are easy to fit or remove and may be mounted to unsprung valves already in service if operating conditions warrant it.
- The result: a fast-closing non-return valve
- Minimizes back flow
- Prevents water hammer
- Highly applicable for high pressure systems