Advantages of Check Valves in Water & Wastewater Systems

Authors: Mike Lassas, President, Proco Products Inc, and Cal Hayes, General Manager, WaterWorks Division

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When you integrate check valves into your piping system, you are making a significant investment in preventative maintenance. Check valves contribute to savings by minimizing both production downtime and equipment damage. This is particularly crucial in scenarios like valve backflow into a pump cavity or during pressure surges, which can cause a reversal of flow. Such incidents can lead to severe damage to vital components within the system. For instance, if there is a flow reversal near the discharge end of a pump, it may force the pump rotor to rotate in the opposite direction, potentially damaging the internal components of the pump.

By implementing a correctly specified check valve, the need for costly repairs or replacements of pumps, along with the associated lost production time, can be effectively avoided.

Check valves offer more than ensuring positive sealing; specialized designs also effectively mitigate valve slam. Valve slam is a widespread issue in water and wastewater facilities, occurring when pumped liquids flow back to the check valve after pump shutdown, resulting in a loud bang. While this noise might be manageable in smaller systems with only a few check valves, large and complex piping systems with hundreds of check valves can experience unbearable noise levels which could also lead to the damage of flanges and gates in some mechanical check valve designs.

The rubber duckbill check valve presents a solution, designed as an alternative to traditional swing gate, inline check valve, and flap gate type check valves. This type of check valve boasts a unique benefit—crafted from a flexible material, it effectively dampens the impact when the pump ceases operation and energy flows upstream. The duckbill design allows it to absorb this energy, thereby eliminating valve slam and preventing water hammer, which can damage pipe supports or, over time, cause ruptures in the piping system.

Rubber duckbill check valves are highly recommended for water and wastewater systems. As liquids flow through the valve, the flow encourages the lips of the valve to open, allowing the pumped media to discharge into an ocean outfall, ditch, or waterway.

Featuring a flange configuration, this inline check valve is available in carbon steel or stainless steel and comes with flush ports on both the top and bottom, facilitating maintenance crews in flushing out potential obstructions—essentially eliminating the need to dismantle swing gate-type check valves and thus reducing maintenance requirements.

In summary, check valves, particularly rubber check valves, provide valuable advantages in preventative maintenance and production uptime:

• Preventing backflow: Check valves are engineered to permit fluid flow in a single direction, preventing backflow during pressure drops or pump shutdowns, safeguarding the system from contamination and damage.
• Protecting pumps: These valves are crucial for protecting pumps from potential damage caused by backflow.
• Reducing water hammer: Check valves minimize the risk of water hammer, a sudden pressure surge resulting from abrupt water flow cessation, by preventing reverse flow.
• Improving energy efficiency: By stopping water from going back to the pump, check valves enhance energy efficiency, ensuring the pump does not work harder to maintain desired flow rates.
• Reducing maintenance costs: Rubber check valves are uncomplicated devices that significantly lower overall maintenance costs for water and wastewater systems.

For further insights into how Proco Products’ preventive maintenance plant surveys help in avoiding downtime, plant failures, and cost implications, we encourage you to explore more.

Additionally, you can watch a video featuring Cal Hayes, Proco Products General Manager, discussing the Proco ProFlex 750 In-Line Flanged Rubber check valve, adept at addressing challenges posed by valve slam.

For more information on check valves from Proco Products, Inc., please reach out to us.