Integrity and life assessment of a shared header

Shared header


Shared HP/IP economiser header, fabricated from A106-C


Determine likelihood of fatigue cracking at the pressure plate and tube-to-header welds, due to thermal stresses on start-up and during steady operation


  • Inverse design analysis
  • Finite element analysis
  • Fatigue life assessment


  • Conservative fatigue lives based on standard materials data for initiation and inverse design procedures did not give adequate confidence for future operation
  • Fatigue lives based on TRD materials data for initiation, accepted crack growth data and stresses calculated by finite element methods from monitored transient and steady-state temperatures and pressures did give confidence in future operation
  • Design changes, although expensive, were identified and implemented

Plant Integrity