Method for monitoring screw connections i.e. flange connections, involves calculating maximum length variation at screw connection based on material strength so as to obtain state about condition of screw connection

摘要

The method involves manufacturing a screw bolt (3) with exact longitudinal dimension, where the bolt is formed as a spindle and a spigot. A screw connection (2) with yield strength of 70-80 percentages of elastic deformation is tightened. Maximum length variation is calculated at the connection based on material strength to obtain a state of the connection. Marks (9, 10) are identified at front ends (7, 8) of the bolt with nominal length tolerance that lies in range of plus or minus 0.02 mm. Flat surfaces of the marks are machined to verify state of the connection. An independent claim is also included for a screw or a screw bolt.