urahaman@gmail.com

NFPA59-2019 Response modification Factor

Discussion created by urahaman@gmail.com on Nov 13, 2019

NFPA 59-2019 edition page 31, section 10.2.2.1 second para (2)  has changed the value of Rp=3, which was 6 in the previous edition. This doubles the seismic force. Is there any reson for this change. As per ASCE-7, this value for piping is 12. We usually used 6.

Also in the first para(1), what is the meaning of "For the OBE design, response modifications shall not be used."  Does it mean that Rp=1 shall be used for OBE? This will then lead to higher OBE acceleration than SSE, which does not make sense.

Request members to explain.

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