Hydrostatic test criteria for the pipings designed with ANSI B31.1(in NFPA 804)

Discussion created by sbkim on May 17, 2017

In the NFPA 804-2015, there are specific requirements, in the paragraph 9.4.7 for the nuclear power plant stating that,

“Sprinkler systems and manual hose station standpipes shall have connections to the plant underground water main so that a single active failure or a crack in a moderate-energy line can be isolated so as not to impair both the primary and the backup fire suppression systems unless otherwise permitted by the following:

(1) Alternatively, headers fed from each end shall be permitted inside buildings to supply both sprinkler and standpipe systems, provided steel piping and fittings meeting the requirements of ASME B31.1, Power Piping, are used for the headers (up to and including the first valve) supplying

the sprinkler systems where such headers are part of the seismically analyzed hose standpipe system.

(2) Where provided, such headers shall be considered an extension of the yard main system.”


To have the headers as an extension of the yard main system in the nuclear power plant, our fire protection yard mains, building standpipes are designed to comply with ASME B31.1, Power piping.


Now, we have an issue about hydrostatic test. ASME B31.1 requires the hydrostatic test with 1.5 times the design pressure (this will be about 270psi) for min. 10 minutes while NFPA 13, 14, 24 states that the test shall be performed at not less than 200psi pressure for two hours, or at 50 psi in excess of the maximum static pressure (this will be 230 psi for our plant). There is some conflict between two codes.


In terms of code compliance on ASME and NFPA, where the pipe is designed with ASME B31.1, which code shall be governed to have headers as an extension of the yard main system in the nuclear power plant?

NFPA standard also references the ASME B31.1 or AWWA code (Paragraph 9.4.1 and Appendix A.9.4.1 states the ANSI/ASME and AWWA is other design codes and standards).


Do we have to follow the hydraulic test criteria on NFPA standard or same applicable design codes, ASME B31.1 code or both?


I am looking forward to hearing from NFPA staff and members.