TRIPLE AXIAL EXPANSION JOINTS
WITH INTERLOCKING
FLOW LINER ARRANGEMENT

For an oil refinery in Germany, Belman has successfully manufactured ten special Triple Axial Expansion Joints with an interlocking flow liner arrangement. These special Expansion Joints are manufactured for a regenerator and will be installed at the hydrogeneration chambers at the oil refinery. Each Expansion Joint will be pressure tested at 52.2 barg.

 

CLIENT ISSUE
As part of the oil refinery is converting parts of its plant into a production unit for a special type of base oil to help reduce carbon emissions, the refinery needed some special equipment – including some special Expansion Joints. To safely and effectively absorb the axial movements of +/-30 mm generated during operation, Expansion Joints with a tailored design were needed. They not only had to fit the existing connections but also withstand the demanding application. For this reason, the client was looking for a highly experienced Expansion Joint manufacturer with proven expertise in unique, complex solutions – and chose Belman.

 

BELMAN SOLUTION

Triple Axial Expansion Joints with interlocking flow liner arrangement

To meet the client’s requirements, Belman designed the Expansion Joints fully in accordance with the provided specifications and drawings. The solution consists of three Axial Bellows placed inline within the assembly. Column instability of the Bellows is prevented by the integrated middle pipe/flow liner. The three DN 100 Bellows are made from Inconel 625 (2.4856) and are designed for the full pressure, for absorption of +/-30 mm axial movement, and for direct contact with the process media. All other components of the Triple Axial Expansion Joint with interlocking flow liner arrangement are manufactured from 1.4541 (AISI 321). The choice of materials was determined by the client to match both the operating parameters and the installation point requirements. Based on the operating data at the installation point, the Expansion Joints are designed for 35 barg; in line with the client’s requests, however, they were pressure-tested at 52.2 barg. Comprehensive testing and full traceability as well as a manufacturing data book (MDB) were included in this project. In addition, thorough calculations and analysis were carried out including risk and hazard analysis. Belman had an existing WPS for welding the assembly in accordance with the specifications, ensuring compliance without additional costs for the client.

 

What is the purpose of Axial Expansion Joints?

In this high-temperature, high-pressure system, the Triple Axial Expansion Joint serves the purpose of absorbing thermal expansion in the axial direction. This helps to prevent stresses and distortion on the regenerator components and connected piping, ensuring mechanical integrity is maintained and prolonging the equipment’s service life. Controlling stress distribution also contributes towards safer operation, reducing unplanned shutdowns and extending maintenance intervals. It is however important to note that while Axial Expansion Joints represent a simple and effective solution for accommodating movement, they always require fix points and/or guides to perform correctly.

 

Why choose the special interlocking flow liner arrangement in the Expansion Joints?

The special pipe arrangement acts as flow liner and ensures that none of the Bellows are overloaded. The flow liner inside the Expansion Joint is designed to control the Bellow’s movement absorption, securing an even distribution of axial movement across all three Bellows. In this way no Bellow is overloaded. This principle of equal distribution of movement between the Bellows is well-known from the pantograph gimbal designs and from the tie rods with their strategically placed stop blocks concept. This latter concept forms the basis of this construction, enabling reliable performance and safeguarding the Bellows against excessive stress.

 

Assembly of the Bellows with client items

The client had very strict tolerance requirements. This meant that components such as the piping of the flow liner arrangement, including the bayonet flanges, Expansion Joint lenses, connecting pieces and the flow liner itself, had to be specially machined. To ensure efficiency and precision, Belman and the client agreed that the best and most efficient solution would be that these parts were produced by one of the client’s trusted partners and then shipped to Belman. Belman would then produce the Bellows and assemble them with the parts delivered by the client into the entire Expansion Joint. In addition to this, Belman pressure-tested the final units. This collaborative approach was the most cost-efficient solution for the client in this case – even though it reduced Belman’s scope of supply. For us, what matters most is that the client receives the right solution: durable, reliable and fit for purpose. 

 

Belman – highly experienced in special Expansion Joint assemblies and flexible solutions for oil refineries

Since 1994, Belman has been supplying special Expansion Joint solutions to refineries worldwide. This extensive experience allows us to design and manufacture reliable, efficient and cost-effective Expansion Joint solutions tailored to the exact demands of each client and application. In some cases, this involves delivering special assemblies, while in others it includes assembling Belman-manufactured components together with client-supplied parts. Belman has successfully carried out numerous solutions such as this.

In addition to client-specific assemblies, Belman’s expertise in Expansion Joints for oil refineries also covers:

• Custom-engineered Expansion Joint solutions such as Hinged, Tied, Ring Reinforced, Pressure Balanced and Elbow, among many other designs.
• Tank Farm Bellows
• FCCU Expansion Joints
• Clamshell Bellows
• Refurbishments/renovations of Expansion Joints