What is a common reason for including a reverse-flow check with a PRV?

What is a common reason for including a reverse-flow check with a PRV?

• A. A pressure spike could close the PRV
• B. An extra valve can't hurt anything
• C. It is needed for safety
• D. All of the above

Answer: (A)

A reverse-flow check is added because a sudden pressure spike can push water back through the valve as the pressure reducing valve responds, which can cause the valve to close or malfunction if backflow is possible. The downstream check valve blocks any reverse flow, so the PRV can regulate downstream pressure reliably without being forced to carry flow back toward the source. While safety and extra components are important considerations, the most practical and common reason cited is preventing backflow during pressure transients, which helps maintain stable operation of the reduction and protects the upstream system from backflow effects.

A reverse-flow check is added because a sudden pressure spike can push water back through the valve as the pressure reducing valve responds, which can cause the valve to close or malfunction if backflow is possible. The downstream check valve blocks any reverse flow, so the PRV can regulate downstream pressure reliably without being forced to carry flow back toward the source. While safety and extra components are important considerations, the most practical and common reason cited is preventing backflow during pressure transients, which helps maintain stable operation of the reduction and protects the upstream system from backflow effects.