Metal Expansion Joints and Metal Bellows

Hinged Expansion Joints

MWP & MFP Series

These expansion joints are made of one single bellows element fitted with welding ends or flanges plus a system of articulated supports which allow for angular movement in one plane only. The hinge mechanism is designed to accept full pressure thrust.

These units do not allow axial movement however, some types of hinge systems can be provided with holes for the hinge pin that are slotted to allow limited axial displacement. These “slotted hinge” types can not resist the pressure thrust forces and therefore proper anchorage must be provided.

Typical Applications

Expansion joint applications. Case 1 diagram
Case 1

Two MWP/MFP Hinged Expansion Joints or one single MWY/MFY double Expansion Joint can be used to absorb the thermal expansion in a Z-shaped section of piping which only occurs in one plane.

Expansion joint applications. Case 2 diagram
Case 2

In the case of pure angular movement these Expansion Joints can be used to absorb expansion in a specific section of piping.

Expansion joint applications. Case 2 diagram
Case 3

There is a different angle than 90º in the section of piping.


  • Single hinged
  • MWP
  • MFP
Pressure Thrust Restrain

Transmits shear and wind loads

Supports dead weight

Avoid twisting the bellows

No main anchors required