Q: I read where the annual fire pump test requires a 30-minute churn test but does not differentiate between a diesel or electric pump (as in the weekly test). NFPA 25, 2011 edition requires only a 10-minute churn for the annual test on an electric pump. What happened to the 30-minute churn test?
A: NFPA 25-1998 did require the annual fire pump flow-test for both electric-motor driven fire pumps and engine-driven fire pumps to have a 30-minute churn test at no-flow conditions to begin the test. This was to ensure the pressure relief valve opened to allow circulating water to cool the pump when operating at standby (i.e. no-flow) conditions.
Since CMS adopted the new 2012 LSC, we are now on NFPA 25-2011. Section 126.96.36.199(1) of NFPA 25-2011 dropped the requirement for a 30-minute churn test for the annual fire pump flow-test, but still requires the churn test; it just doesn’t specify how long the churn test must be. I can only surmise that the industry figured a churn test for 30 minutes to ensure the relief valve opens is no longer required.
However, section 188.8.131.52(3) says “For electric motor-driven pumps, the pump shall not be shut down until the pump has run for 10 minutes.” This statement is in reference to the pump operating at flow conditions, and is not a reference to how long the pump must run at no-flow conditions.
The new 2012 LSC is now being enforced by accreditation organizations and by CMS. For annual fire pump flow tests from now on, you may run the churn test portion long enough to ensure the relief valve opens and dumps water. You no longer have to run the churn test for any given length of time.