Patented Flow RestrictorThe current design of all externally pressurized expansion joints has a small gap between the inner pipe (1) and end ring (2) to allow for axial movement, yet limit media loss in case of a bellows rupture.
Patent #: 5,299,841
This design is suitable for axial movement only. If any lateral or angular movement is applied during installation or operation, the inner pipe (1) could bind with the end ring (2) resulting in restricted axial movement and excessive loads on anchors.
Adsco "PM" Pressure Master Externally Pressurized expansion joints with optional Flow Restrictor permit lateral and angular movement to be incorporated into the design of piping systems or installation tolerances.
This feature allows for a larger gap between the inner pipe (1) and the end ring (2) to allow for lateral and angular movement. The patented ring (3) has very close tolerances between the inner pipe (1) and the end ring (2) so that in the event of a bellows failure, leakage will be significantly reduced.