Velocity and Check Valves Relationship
The force generated by water flowing through the spring loaded check valves open the check valves. However, in some circumstances there is insufficient velocity (GPM) to open the checks fully. Low flow through the check valves may not fully open the check valves creating a humm or buzzing sound. A constant low flow through the check valves that are not fully opened my cause the check valve to wear-out prematurely. The check valves are designed to open fully during normal operations of flow. If the backflow prevention device is to large for the design recommended flow, the velocity may not be sufficient for the check valve to function as designed and will only open partially. The backflow prevention device should be sized for the appropriate flow rate. Backflow prevention devices/assemblies with low flow rates may be more prone to fouling due to the buildup of debris on the check valve seat. Flow through the check valves will generally keep the check valve seats free of debris. Low flow rates which do not fully open the check valves may result in undesirable noise and premature check valve failure.
