Stationary Pumps – New Requirements

NFPA 20, Standard for the Installation of Stationary Pumps for Fire Protection, provides requirements for the selection and installation of fire pumps. NFPA 20 is employed when a project’s parameters, i.e. there is no available water supply, or a hydraulic analysis of an available water supply, dictates the need for a fire pump.

In the annual revision cycle of NFPA 20, 264 proposals and 135 comments were received and taken into account in the changes to the 2013 edition of NFPA 20.

This article focuses on some key changes of the 2013 edition and assumes that readers have a basic understanding of water-based suppression systems, NFPA 20, and the role of NFPA in establishing these requirements.

Other pumps

“Other pumps” has been removed from the standard, clarifying that only fire pumps listed as such can be used for fire protection. The provision of “other pumps” had allowed for the use of pumps having different design features other than those specified in the standard provided they were listed by a testing laboratory. This provision was often misinterpreted to mean that it allowed any electric motor-driven pump as a fire pump.

Water flow test data

Where a water flow test is used to determine the adequacy of the water supply, NFPA 20 now requires the test to be performed within 12 months prior to the fire pump plan submittal, unless permitted otherwise by the authority having jurisdiction. This change aligns NFPA 20 with the requirements of NFPA 13 and NFPA 14. Additionally, this new criteria is due to the concern that if older test data were to be used it may not reflect the current water supply conditions, resulting in the possible discovery of insufficient discharge pressures to meet system demands during the acceptance test.

Equipment protection

NFPA 20 requires the fire protection of pump rooms or pump houses and is summarized in table 4.12.1.1.2. The addition of new annex language for the “Not Sprinklered” column of the table clarifies a common misinterpretation that sprinklers can be omitted from a fire pump room in a fully sprinklered building. The intent of the “Not Sprinklered” column is to provide guidance for unsprinklered buildings.

Where a fire pump room is located internally and without access from the exterior of a building, NFPA 20 requires an access passageway protected with a fire-resistive rating. Additionally, NFPA 20 requires that a pump operator respond to a fire pump room upon activation of the fire pump. The passageway provides the operator a safe means of access. Previous editions required a 2-hour rating for the passageway, which was sometimes in excess of the fire pump room rating, but now the two ratings are aligned.

Water flow test devices

When a flow meter is used in a looped arrangement for annual flow testing of the fire pump, the 2013 edition requires that an additional means of measuring flow be provided. This additional measure has to be located downstream of the flow meter so that it may be used to verify the accuracy of the flow meter.

Test header control valve

The previous edition of NFPA 20 required a control valve on a test header only when it was located outside or at a distance from the pump and there was danger of freezing. The 2013 edition revised this section, requiring a control valve in all test header installations. Additionally, a drain valve or ball drip needs to be installed on the test header piping at the lowest point between the control valve and the header. Without the control valve, test header piping would be under system operating pressure up to the header. There are two concerns: first that someone can open the test header hose valves and use them for non-fire protection use; second the safety of those performing the pump test when connecting the hose to the test header hose valves.

Very tall buildings

“Very tall buildings” is a new concept introduced in Chapter 5, Fire Pumps for High-Rise Buildings, of the 2013 edition. The addition of “very tall buildings” provides requirements for high-rise buildings that reach heights beyond the pumping capabilities of the fire department apparatus. The reason for this is to address the possible limitations of fire department apparatus, which may be incapable of overcoming the elevation loss and friction loss in order to achieve the required pressures at the hose outlets in the building.

Due to the limitation of the fire department apparatus to provide a water supply to the upper portion of “very tall buildings,” the fire protection system needs to have additional provisions, including sufficient water supplies and fire pump redundancy. These requirements are performance-based and not based on specific building height. The technical committee made this decision based on the fact that fire departments purchase different apparatus with different pumping capabilities.

More details

To view all the changes made within the revision cycle the reader should visit the Document Information Pages for NFPA 20 at www.nfpa.org/20, Document Information tab. The Report on Proposals and Report on Comments can be found under the “Archived revision information” link.cce

Chad Duffy is a senior fire protection specialist in the division of fire protection systems engineering at the National Fire Protection Association in Quincy, Massachusetts and staff liaison to the Technical Committee on Fire Pumps. He has 19 years’ experience in the field of fire protection systems.