HIGH TEMPERATURE
EXPANSION BELLOWS

Belman recently engineered and manufactured seven High Temperature Expansion Bellows, this was a noteworthy order due to the special materials involved. The material  alloy 188 – same material as used for mars equipment. The Expansion Bellows will be installed in an innovative green energy solution for the shipping industry, thereby making this also a highly interesting and environmentally friendly project. The client is very experienced in designing these types of systems but for this project needed expert advice on the Expansion Bellows.

 

Client challenge – Design temperature 900°C (1652°F)

The Expansion Bellows to be installed in this innovative solution need to absorb both axial and lateral movement generated by the process. Further, the design temperature is very high at 900°C (1652°F), and therefore sets critical demands for the Expansion Bellows. The client required expert advice concerning questions such as the best design for the application, the most suitable material and how to minimize spring rates. Belman provided the high level expertise required and working in close cooperation and in a spirit of mutual interest proposed a solution that delivered the maximum possible benefit to the client.

 

Belman solution – Very special material Alloy 188

In this project temperature and flexibility were the main items of concern. Particularly challenging was the selection of material with sufficient resistance, strength and flexibility needed to ensure operation. Three high temperature materials were identified as having potentially the right characteristics: 253 MA, Alloy 188 and Alloy 230. 253Ma was rejected due to its insufficient flexibility and strength which would be unsuitable for the required spring rates. The two alloys 188 and 230 were examined further as both materials offered potentially good solutions for high temperature applications with better flexibility and lower spring rates.
As the flexibility of the Alloy 188 is slightly better than Alloy 230 – this material was finally selected for the High Temperature Expansion Joints. Alloy 188 is a cobalt-nickel-chromium-tungsten alloy that offers excellent high-temperature strength, thermal stability and superior oxidation resistance up to 1095°C (2000°F). It is 17 times stronger than Inconel 625 at elevated temperatures. However, during the manufacturing process care must be taken when working with this alloy as it contains Wolfram. Radioactive dust can be released during grinding which can present a health hazard to the workforce and the environment. However, Belman has deep expertise in working with special materials and was able to plan the work accordingly and avoid any possible risks.

 

Material family used in equipment landing on the planet Mars

Aside from elasticity Alloy 188 and Alloy 230 share many of the same properties, making this family of materials interesting for extremely critical applications involving high temperatures. For that reason, this material family was chosen for equipment used in super demanding applications in space exploration missions, for example to withstand the high temperatures when entering the Martian atmosphere. The MR-80B throttling decent thrusters of the “Sky Crane” delivery vehicle used to lower the Mars 2020 Perseverance Rover down to the Martian surface also incorporated these alloy types.

 

Belman always brings its A-game

Belman is known for bringing its A-game every time. This is why clients with critical projects turn to Belman for assistance. With a successful track record stretching over more than 25 years, Belman has gained a vast experience from a wide array of challenging projects and has manufactured Expansion Joints from many different materials and for many varied applications. Belman uses this deep expertise to always find the optimal solution to the challenge. We are not afraid of challenging our own capabilities and we know our strengths very well. Our philosophy is that there is always a way to get the job done, and our engineers and welders always go above and beyond to create the right solution to solve the client’s challenge. See other projects were Belman has made significant value for the client from our latest projects