New tolerance standard for installation of piping supports in nuclear power plants

When the support positions are shifted from the designed position up on installation, the designer must decide whether the new support position is acceptable. Evaluation of these support shift effects led to the following new support installation tolerance standard proposed: (1) The support shift value is evaluated in terms of the design margin and the response fluctuation ratio for the support shift. (2) The response fluctuation ratios are determined in the case of the single-support position shift and the single-support angle shift. (3) The response fluctuation values for multiple support shifts are given by the square root of the sum of the square of the response fluctuation value for the single-support shift