Factors Affecting Nut Factors for PVP Bolted Joint Assembly

This paper addresses recent findings with respect to the effect of different manufacturing defects which, while currently compliant with the industry standard purchase specifications (ASTM A193 and ASTM A194) had a significant impact on the obtained nut factor in laboratory testing. The level of impact on the obtained nut factor was found to be significant enough that the likelihood of joint leakage would have increased several-fold. These defects have been found to be relatively common in bolts delivered for testing and simple modifications to the industry standards are proposed in order to remedy the potential for any such defect causing joint leakage