August 29, 2018

ASME U Stamped Externally Pressurized Expansion Joints

MEP Series Externally Pressurized Expansion Joints are designed such that fluid pressure acts on the outside of the bellows.

This time we have designed, manufactured and tested three MEP Series Externally Pressurized Expansion Joints DN1117, DN1149 and DN355 mm.

These expansion joints are manufactured entirely in stainless steel A240 Tp 304H (a high carbon content stainless steel making it more suitable for applications where elevated temperatures are present). It is an austenitic chromium-nickel steel alloy and the greater carbon content provides also an increased tensile and yield strength.

This MEP Expansion Joints have been ASME U Stamped and undergo a comprehensive quality control and testing program including:

  • ASME Inspection, Partial Data Report, Form U2.
  • Review Drawings
  • Advanced Review of Calculations
  • Check Material and welding consumables certificates
  • Review and update WPS, PQR and WQR
  • Review NDE Procedures & Operator Qualification
  • 100% Visual inspection of welds.
  • 100% RT- Radiographic Examination
  • 100% PT - Liquid Penetrant Examination
  • Hydrostatic Pressure & Leak Detection Test
  • 100% PMI - Positive Material Identification¬†

This model is mainly used in cases of high pressure and large amounts of axial compression and extension. When under external pressure, the bellows will retain its shape and can be manufactured in almost any length.

When using internally pressurized expansion joints and for large movements the system should be divided into subsections, as internally pressurized axial expansion joints tend to become instable with a great length. When the system allows their use, expansion joints with externally pressurized bellows can be used, which permit larger movements, since external pressure tends to stabilize the bellows.