Expansion joint stops pipework moving

The PosiFlex elastomeric expansion joint from Crane is a means of compensating for movement in pipework that has been well-proven in a wide range of industries

The PosiFlex expansion joint accommodates all types of movement in the pipes to which it is connected - axial (expansion/contraction), lateral, angular, torsional, and vibration - simultaneously and without embrittlement or fatigue.

It absorbs large pipe movements with minimal face to face dimensions, and has been found useful in the power, water and waste treatment, process, pharmaceutical, marine, HVAC, petrochemical, chemical and food industries.

This flexibility (in every sense) means that fewer expansion joints are needed, and their low spring rates reduce the stress on the pipework system - features that together give a high degree of predictability and consistency, enabling piping and stress engineers to anticipate movement and design accordingly.

In addition to compensating for movement, the PosiFlex joint provides an effective means of reducing noise or vibration.

Unlike predominantly metal devices such as metal expansion bellows, it also resists corrosion and erosion.

For pipework which is not anchored, Crane can provide control units with a rod assembly that limits end thrust in the joint and minimises possible damage from excessive movements of the pipeline to both the joint and other installed equipment.

The units are sized to match the project, and can be retro-fitted.

Strong polyester reinforcement, which is especially important for pressure or vacuum applications, is a standard feature of all PosiFlex joints.

Larger sizes incorporate a vacuum support ring embedded into the carcass, providing strength and ensuring minimal distortion without contact with the medium being conveyed.

Other reinforcements are readily available and include nylon, Kevlar and fibreglass.

Selection of reinforcement is dependent on both temperature and pressure.

Other options include double, triple and quadruple joints to allow for additional movement; and filled arch models, which are ideal for slurry applications.

Expansion joints can be manufactured from seven different rubber compounds to accommodate the needs of pipe systems conveying media as diverse as foodstuffs, chemicals and crude oil.

The range of elastomers includes EPDM, neoprene, chlorobutyl, nitrile, Viton, Hypalon and natural rubber.

The Crane PosiFlex elastomeric expansion joint is a full-bore product that allows unobstructed flow of the medium and reduces cavitation and turbulence.

Easy-to-install segmented retaining rings enable full flange face sealing that is maintained under all movement conditions.

Sizes from DN40 to DN3600 are supplied, with flanges to all widely used specifications - PN, DIN, ANSI, and AWWA.

PosiFlex expansion joints are designed and manufactured to the Fluid Sealing Association standard under quality control management systems certified to BS EN ISO 9001:2000.

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