Single Untied Expansion Joints consist of a single bellows element welded to end fittings—normally flange or pipe ends. They can absorb small amounts of axial, lateral, and angular movements with ease. However adequate anchors and guides must be provided.
Single Tied Expansion Joints also have one bellow. Except that their length is restrained by the use of tie rods that can accept pressure generated thrust. When under pressure, they are usually not designed to accept any axial movement but can accept lateral movements.
Universal Untied Expansion Joints consists of 2 bellows connected by a center spool piece with flange or pipe ends. The universal arrangement allows greater axial, lateral, and angular movements that a single expansion joint. Increasing the center spool length produces increased movement capability. Like the single, adequate anchors and guides must be provided.
The addition of tie rods to a Universal Bellows Assembly adds design flexibility to the piping system in that they carry the pressure thrust of the system, eliminating the need for main anchors. However, with the assembly tied, the ability to absorb axial movements is lost. Only lateral and angular movements can be absorbed with Tied Universal Expansion Joints. Guiding system is still required.
Standards :
Design Ranges :
- Sizes up to 9000 mm.
- Pressures from full vacuum to 200 bars.
- Temperatures from cryogenic to 1250 degrees C.
- End connections—flanged or welded ends.
- Material—all grades of austenitic stainless steel and high nickel alloys.
Features & Benefits (display in the optional box):
- Radiographic examination of welds.
- Ultrasonic examination of possible defects.
- Liquid penetrant examination of possible defects.
- Magnetic particle examination of possible defects.
- Fluorescent penetrant examination.
- Mass spectrometer examination of leaks.
- Pneumatic pressure testing.
- Air jet leak examination.
- Hydrostatic pressure testing