What is the difference between static and dynamic testing in NFPA 20 acceptance testing?

What is the difference between static and dynamic testing in NFPA 20 acceptance testing?

• A. Static testing verifies pressure with flow
• B. Visual inspection
• C. Dynamic testing verifies pressure and flow with pump operating
• D. Electrical insulation test

Answer: (B)

In NFPA 20 acceptance testing, the difference comes down to whether the system is tested with the pump stopped or with the pump running. Static testing is performed with the system at rest and no flow, to verify the piping and components can withstand the pressure when the system is charged but not delivering water. Dynamic testing, on the other hand, is conducted with the pump operating and water flowing, to confirm the pump can produce the required pressure at the intended flow rate and that the overall system performs as designed under actual operating conditions. Visual inspection is an important part of acceptance testing to confirm proper installation and condition, but it does not define the difference between static and dynamic testing. The notion that static testing verifies pressure with flow is incorrect because static testing uses no flow. Conversely, dynamic testing does involve pressure and flow with the pump running, which is the essence of that test stage.

In NFPA 20 acceptance testing, the difference comes down to whether the system is tested with the pump stopped or with the pump running. Static testing is performed with the system at rest and no flow, to verify the piping and components can withstand the pressure when the system is charged but not delivering water. Dynamic testing, on the other hand, is conducted with the pump operating and water flowing, to confirm the pump can produce the required pressure at the intended flow rate and that the overall system performs as designed under actual operating conditions.

Visual inspection is an important part of acceptance testing to confirm proper installation and condition, but it does not define the difference between static and dynamic testing. The notion that static testing verifies pressure with flow is incorrect because static testing uses no flow. Conversely, dynamic testing does involve pressure and flow with the pump running, which is the essence of that test stage.