Axial Expansion Joints

Lateral Expansion Joints

Hinged Expansion Joints

Universal Expansion Joints

Gimbal Expansion Joints

Inline Pressure Balanced Expansion Joints

Elbow Pressure Balanced Expansion Joints

Externally Pressurized Expansion Joints

Pump Connector Expansion Joints

Exhaust Gas Bellows Expansion Joints

Rectangular Expansion Joints

Heavy Wall Expansion Joints

Bellow Elements for Expansion Joints

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The in-line pressure balanced expansion joints are designed to absorb externally imposed axial movement without imposing pressure loading on the system. This is accomplished by using two bellows both at line pressure tied together and acting in opposite directions. It is used where pressure loading on the piping or equipment is not acceptable.

While the joint balances out the pressure forces , the force required to move the joint itself is not balanced. Both the flow bellows and balancing bellows must be compressed or elongated in operation and the combined axial spring force acts on the piping or equipment. Since the forces need to move the bellows of the in-line pressure balanced expansion joints are of low magnitude these are usually not objectionable.

  Pressure balanced expansion joints for high pressure steam

In-line pressure balanced expansion joints are usually installed at change of direction. They may also be designed for in line operation.

The complexity of the  in-line pressure balanced expansion joint makes it an expensive unit . It�s use can be justified economically only in those cases where the problems created by the pressure loading would be even more expensive.

The in-line pressure balanced bellows is a unique design which absorbs thermal motion while eliminating the pressure thrust loads on a piping system without a change in the direction of the piping.

The design of the in-line pressure balanced bellows consists of a constant volume device which is created by the addition of a balancing bellows whose cross sectional area is exactly twice the cross sectional  area  of the line or flow bellows . By proper cross  linking the change in the volume of the line or flow bellows due to change in the length ( i.e. due to compression or extension) can be made to cause an equal but opposite change in the volume of the balancing bellows. Thus since the volume changes are of equal value the pressure forces that are normally present in the piping system containing bellows expansion joints are eliminated.

In-line pressure balanced expansion joints are used  where the location of the expansion joint prohibits or makes it very costly to install main anchors.

  In-line pressure balanced expansion joint