January 22, 2020

High Pressure DN 5200 Expansion Joint for ExxonMobil in Scotland, UK.

A reinforced MRR Series Expansion Joint of 5200 mm diameter and 9,35 barg design pressure has been successfully designed, manufactured and tested for ExxonMobil in Scotland.

This expansion joint combines all the elements to make it a very critical unit, as much in its construction as in all the tests and examinations carried out.

Main mechanical design, parameters and features of the expansion joint supplied are:

  • Design Code: ASME VIII div.1 / EJMA / PED 2014/68/EU with CE marking module G
  • Design Pressure Shell side: 9,35 barg
  • Design Temperature Shell side: 518 /-9 °C. (max./min.)
  • Material for bellow: ASME SA-240 TP 304H – Heat Treated after forming
  • Materials for shell weld ends: ASME SA-387 Gr.91
  • Material for reinforcing rings: ASME SA-240 TP 304H

Due to the welding of the 304H convolutions to the Gr.91 weld ends, the heat-affected zones are susceptible to relaxation cracks. This weld requires PWHT as well together with the longitudinal seams in the Gr.91 weld ends. 100% NDE (RT) before and after PWHT have been carried out.