Tag: Expansion Joint Accessories

Duct work assemblies can include fabricated elbows, tees, straight sections of duct work, fabric or metallic expansion joints and can be rectangular or round.

It is recommended that all expansion joints include liners in order to protect the bellows from the internal flow environment.

A movement guide controls the thermal motion of the piping system into the bellows

Expansion couplings are used mainly to connect two pieces of pipe together.

Usually, the liner material can be the same as the system pipe material, such as carbon steel, with liner thicknesses of 1/8-inch and greater depending upon flow rate and diameter.

The growth of an expansion joint bellows is restrained with the use of limit rods.

Internal liners are an expansion joint accessory used to protect the convolutions from direct flow impingement, which can cause erosion and flow-induced vibration. They are recommended to extend the life of metallic expansion joints.

Yes for a simple bellow, the tie-rods main purpose is to hold the pressure thrust.

Pressure thrust can be absorbed by placing anchors in a system or by using an expansion joint with tie rods.

A directional anchor restrains the pressure thrust from the expansion joint and allows for movement in a direction perpendicular to the pressure thrust.

The tie rods are used to take the pressure thrust forces. Most universal expansion joints use tie rods to eliminate the requirements for main anchors

Pantographic linkage is an accessory that is used to distribute axial movement between two bellows, allow lateral motion and support the weight of the center pipe section between the bellows.

The number of tie-rods used is determined by the design pressure of the expansion joint. It can range from two to eight tie rods in extremely high-pressure conditions.

Control rods are used to control axial and lateral movements of the expansion joint.

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Limit rods are used to limit axial expansion or compression to prevent the bellows from over-compression. Limit rods are designed to absorb the pressure thrust of the expansion joint in case of anchor failure.

The function of tie rods on an expansion joint is to continuously restrain the full pressure thrust during normal operation while permitting only lateral deflection. Angular rotation can be accommodated only if two tie rods are used and located 90 degrees opposed to the direction of rotation.