Swing Check Valves Vs. Weight and Lever Check Valves
In this article, Disai valve discuss the various terms associated with Check Valves.
Whether it's a resilient hinge check valve or a swing check valve, these valves find common use in pumping applications across the water and wastewater industry.
Additionally, a comparison is drawn between swing check valves and the conventional Weight & Lever Check Valve.
Swing Check Valves, Resilient Hinge Check Valves, and Weight and Lever Check Valves are frequently used.
Explore the distinctions between Swing Check Valves and Resilient Hinge Check Valves here.
The article delves into whether resilient hinge check valves outperform weight and lever valves or if both have their respective applications.
It provides insights into the advantages of opting for a resilient hinge check valve over a weight and lever check valve in pumping scenarios.
Both Swing Check Valves (or Resilient Hinge Check Valves) and Weight and Lever Check Valves fall under the category of 'Non-return valves.'
These valves primarily serve the purpose of safeguarding the pump from potential surge pressures that may occur after pump shutdown in a pumping station.
The traditional weight & lever swing check valve exhibits an 80-90° stroke from fully open to fully closed, necessitating an external weight and lever to expedite disc closure.
The reliance on gravity alone is inadequate for swift valve closure, prompting the use of a 'weight' to prevent reverse velocities, which could otherwise cause damage to the disc, seat, and surrounding pipework.
The Weight, Lever, Hinge, and Disc assembly, comprising up to a dozen components, can lead to issues such as rag snagging in wastewater applications, potentially obstructing the valve's proper sealing or causing a complete blockage.
Health & Safety regulations and WIMES mandate the protection of the weight and lever by a guard to prevent injuries.
However, the historical practice of removing the guard for tasks like deragging the valve, back-flushing the pump, or verifying pump operation often occurs due to capital expenditure pressures.
Further issues arise from the Weight, Lever & Hinge assembly:
The Resilient Hinge Check Valve was initially designed to facilitate clog-free flow in vertical orientations. The valve incorporates a steel and nylon-reinforced molded disc & hinge assembly, relying on a guaranteed, repeatable elastomer as its spring, and features a 35° stroke to typically reduce closing speed by a third.
If you have encountered these products in water or wastewater applications, please share your experiences.