Tuesday, October 1, 2019

UL 448 - Fire Pump Horse Power Changes

Effective November 1, 2019, Underwriters’ Laboratories (UL) Standard 448 has been revised to change the maximum horsepower required by the driver (electric motor or diesel engine) paired with a fire pump. The new requirement specifies that maximum brake-horsepower must be demonstrated during each performance test. If the maximum horsepower developed is greater than current motor or engine horsepower offering, the pump will fail testing under the new criteria. This is an industry-wide change, meaning compliance is required by all UL listed fire pump manufacturers.

To maintain compliance with the Standard, driver requirements for numerous fire pumps have changed for all manufacturers with any orders shipped beginning November 1, 2019.

Vertical turbine fire pumps, by the nature of their design, are not affected by the change in Standard.

The UL448 Standard pertains only to centrifugal pumps, therefore positive displacement pumps, are not affected by this change. 


Does this change in the UL448 Standard affect both electric-driven and diesel-driven fire pump packages? Yes, this change applies to both electric and diesel fire pump packages.

You state “maximum brake-horsepower must be demonstrated during each performance test.” Haven’t fire pumps always been tested this way? Until now, fire pumps have been tested up to shortly beyond the secondary duty point (i.e. 150%) and not to runout (can be up to 400% of the pump rated flow)

What about replacement pumps? Might they need higher horsepower drivers or are they “grandfathered” in? All fire pumps shipped after November 1, 2019 must be compliant with the new UL448 Standard, meaning some horsepower requirements may increase. This applies to replacement pumps, as well as pumps for new installations since they all must undergo Certified Performance testing and demonstrate the maximum brake horsepower during this test. Rotating elements can be replaced like-for-like.