INNER SLEEVES IN 1.4828 (AISI 309) DUE TO HIGH TEMPERATURE

For a blast furnace in Germany, Belman has engineered and manufactured four 1:1 replacement Expansion Joints identical to the previous solution. This provided the client with a proven, reliable solution while avoiding the need for additional testing and third party approvals.

CLIENT ISSUE
In the hot-air pipeline on its blast furnace, the client was looking to replace four Expansion Joints that had reached the end of their long service life. The original design had performed very well, so the client wanted a manufacturer capable of designing and manufacturing four new Expansion Joints with the exact same design – making it a 1:1 replacement.

BELMAN SOLUTION – exact same Expansion Joint design 

To fulfil the client’s requirements, Belman designed a 1:1 Expansion Joint solution identical to the existing solution. Only a few modifications were made on the flexible part; however, these did not have any impact on the length or any of the other features of the Expansion Joints. The original design included a round gimbal, which are known to be more space-saving than square gimbals. The yellow transport bars were fixed to lock the gimbal in place during transportation and handling. The coating and the materials of the Compensators was as per client request.

Compensator inner sleeves made from material 1.4828 (AISI 309)

The medium in the pipeline of the installation operates at a temperature of approximately 900°C, requiring both the pipeline and the Expansion Joints to be refractory lined to ensure a much lower skin temperature. This allows the Expansion Joints to be designed for a temperature of just 120°C, using materials such as 1.4571 and 1.0425 respectively. As concrete is not flexible, there are openings in the refractory lining at the flexible part of the Expansion Joint. At this opening, the exposed steel needs to be resistant to the high internal media temperature. For that reason, the inner sleeves of the Expansion Joints are made from 1.4828 (AISI 309), which is a heat-resistant, austenitic chromium-nickel-stainless steel-resistant scaling up to 1000°C.

Test and third party approvals avoided due to 1:1 replacement
When new components as well as redesigned components are installed in a plant, including Expansion Joints, test and third party approval is, in most cases, necessary. In this case, by doing a 1:1 replacement with only slight modifications on the flexible parts, no further testing or third party approvals were needed. Belman, however, conducted a pressure test and a visual test as per agreement with the client.

Belman – extensive track record of Expansion Joints for steel plants
Since 1994, Belman has engineered custom-built Expansion Joint solutions for clients in many different industries globally and Belman has accumulated extensive experience within the design and manufacture of Expansion Joints for steel plants. Over the years, we have consistently supplied all kinds of customised Expansion Joints for steel plants worldwide. This solid track record of references for steel plants and other clients includes the heaviest Expansion Joint ever made by Belman, which weighs 40 tonnes. Belman is well-acquainted with the preferred design codes for Expansion Joints for steel plants and also has vast expertise in handling the stainless steel materials often required for these applications. These materials include, but are not limited to, Hardox 400, P355NH and Inconel 625.