METHOD AND AUXILIARY TOOL FOR MEASURING CLAMPING FORCE OF EXISTING CLAMPING BOLT AT FLANGE JOINT

摘要

PURPOSE:To apply a method for computing clamping force based on an elongation caused by clamping even in cases wherein lengths and relationship between a load and strain under no-load state are not known by mounting a pair of holding arms in the vicinity of an existing clamping bolt, and manipulating the already provided bolt and a measuring bolt so that the interval at the inside of a flange joint becomes constant. CONSTITUTION:A pair of holding arms 1a and 1b are mounted in the vicinity of an existing clamping bolt 12 at a flange joint 10. The interval between the inner surfaces of the holding arms is measured. Then the arms are clamped with a clamping part 4 comprising a measuring bolt 2 for the holding arms and a nut 3. The clamping amount is gradually increased. Then, the bolt 12 and a nut 13 are loosened so that the interval between the inner sides of the holding arms becomes equal to the initial length. Then, the clamping force of the bolt 12 is gradually transferred to the bolt 2 through the holding arms. Therefore, the bolt 12 is gradually shortened, and the bolt 2 is gradually elongated. When all clamping force of the bolt 12 is transferred to the bolt 2, the length of the bolt 2 is no longer changed thereafter. Only the interval between the inner sides of the holding arms becomes narrow. Therefore, the clamping force of the bolt 12 can be measured based on the clamping force of the bolt 2 when the length of the bolt is not changed any more.