18-04-2012, 01:26 PM
Thermal and Structural analysis of pipe joints during In-service welding process
ABSTRACT
In-service welding is one of the many applications of welding methods which has a wide use in petrochemical and gas industries.
The safety of the in-service welding is a major concern and the investigation of the Burn-Through and Hot-Cracking risks is becoming an important issue.
In the present study, the effects of two major parameters . (a) main pipe thickness; and (b) the amount of heat input (electrode diameter) will be investigated on the burn-through risks during the in-service welding of a pipe branch connection on a steam pipeline at full line pressure to perform hot tapping
A Finite Element (FE) based thermal and structural analysis will be carried out to model the in-service welding.
To assess the burn-through risks, current recommendations only rely on the observation of the main pipe inner wall surface temperature. However, this criterion does not take into account the effect of mechanical stresses due to the inline pressure.