Expansion Joint

Expansion joint Highlights

The expansion joint can prevent excessive horizontal/vertical stresses in pipelines .They stop bursts and leaks caused by vibrations during fluid flow. The core of the expansion joint is the metal bellows. Darko's metal bellows utilize advanced modern design and manufacturing processes, and all the bellows have the following advantages:

• High elasticity
• Short length
• Large compensation capacity
• Durability and excellent chemical resistance

Common application fields

Metal expansion joints are widely used in various pipeline systems, such as in the oil, chemical, power, steel, and construction industries.

In the oil and chemical industries, metal expansion joints are more common. They are needed for high temperature and high pressure media.

In the power industry, metal expansion joints are used at pipeline system interfaces. They ensure the safety of the pipeline connections.

Metal expansion joints are a very important device in pipeline systems. They can ensure the stable operation of the pipeline system and extend the service life of the pipeline.

Main Types

1.Single Axial Expansion Joint

This type includes one corrugated pipe and two short connecting pieces that link to it. It primarily absorbs axial displacement but cannot balance the pressure thrust of the corrugated pipe.

2.Single Hinge Expansion Joint

This type includes one corrugated pipe, short sections at both ends, and components such as a standing plate, hinge plate, and pin shaft that connect to it. It primarily absorbs angular displacement within a single plane and balances the pressure thrust of the corrugated pipe.

3.Single Balance Ring Hinge joint

This type consists of one corrugated pipe. The short sections are at both ends. It also includes components such as a pin shaft, hinge plate, universal ring, and standing plate that are connected to it. It primarily absorbs angular displacement in any plane. Additionally, it can withstand the pressure thrust of the corrugated pipe.

4.Double Universal joint

This type consists of an intermediate connecting pipe that links two corrugated pipes. The short outer sections connect to the corrugated pipes. It also includes related structural components. It is primarily used to absorb combined axial and lateral displacement. Additionally, it cannot balance the pressure thrust of the corrugated pipes.

5.Double Tie Rod joint

This type consists of an intermediate connecting pipe that links two corrugated pipes. The short outer sections connect to the corrugated pipes. It also includes tie rods, end plates, spherical gaskets, and conical gaskets, along with related structural components. It is primarily absorbs axial displacement and lateral displacement in any plane. Additionally, it can balance the pressure thrust of the corrugated pipes.

6.Double Hinge Bellow

This type consists of an intermediate connecting pipe that links two corrugated pipes.The short outer sections connect to the corrugated pipes. It also includes pin shafts, hinge plates, standing plates, and related structural components. It primarily absorbs lateral displacement within a single plane. Additionally, it can withstand the pressure thrust of the corrugated pipes.

7.Double Universal Hinge Bellow

This type consists of an intermediate connecting pipe that links two corrugated pipes. The short outer sections connected to the corrugated pipes. It also includes cross pin shafts, hinge plates, standing plates, and related structural components. It is a composite hinge expansion joint. This joint functions similarly to a single hinge expansion joint but can absorb larger plane angles.

8.Bend Pipe Pressure Balanced Bellow

This type consists of one corrugated pipe or an intermediate connecting pipe that links two main corrugated pipes and a balance corrugated pipe. It also includes short outer sections connected to the corrugated pipes. Additionally, it has elbows or tees, end caps, tie rods, end plates, spherical gaskets, and conical gaskets, along with related structural components. It is used to absorb any combined axial and lateral displacement. Furthermore, it can balance the pressure thrust of the corrugated pipes.

9.Straight Pipe Pressure Balanced Bellow

This type consists of two corrugated pipes located at both ends. There is a balance corrugated pipe in the middle. It also includes tie rods or tongue pipes, end plates, and related structural components. It primarily absorbs axial displacement. Additionally, it can balance the pressure thrust of the corrugated pipes.

10.External Pressure Single Axial Bellow

This type consists of a corrugated pipe that withstands external pressure. The short sections connect to it. It also includes an outer pipe and end rings, along with related structural components. It primarily absorbs axial displacement. Additionally, it cannot withstand the pressure thrust of the corrugated pipe.