CRYOGENIC
EXPANSION BELLOWS

These engineered Cryogenic Expansion Bellows (18 pieces in total) were engineered, manufactured, and tested for installation in a Floating Storage and Regasification Unit (FSRU) that will operate in a gas fired power plant in El Salvador. This is part of a LNG-to-power green initiative project, whereby the Cryogenic Expansion Bellows will be delivered firstly to a shipyard in Singapore where an LNG carrier is being converted into a FSRU.

Client challenge – a combination of critical operating parameters
The application involves the critical transportation and storage of liquefied gas under challenging conditions, this is combined with the installation point on the FRSU operating with extremely low temperature, high pressure and large lateral movements. All these factors when added together creates high demands for the installed equipment and therefore requires the need for a highly engineered Cryogenic Expansion Bellows solution. The solution was certified to high standards and strict regulations (IGC codes/DNV). Furthermore, as the media concerned (LNG) is extremely dangerous should it leak, the safe operation is of paramount importance. The use of Cryogenic Expansion Bellows provided an extraordinary safe solution for the application. The client relied on Belman for specialist assistance and close and mutual cooperation in order to find the best Cryogenic Expansion Bellows solution for their unique needs.

The Belman Solution
The combination of extreme working conditions, the corresponding design requirements and the addition of the high demands within LNG (IGC/DNV) provided a considerable challenge. Belman worked closely with the clients engineering team to propose a robust, durable and cost-efficient Cryogenic Expansion Bellows solution. During the initial online meeting, the client presented Belman with the existing Cryogenic Expansion Bellows and Belman duly responded with a Cryogenic Expansion Bellows design which incorporated the required improvements with the given parameters. Based on this and the pipeline data provided by the client, Belman calculated a cost-efficient and sound Cryogenic Expansion Bellows design. Useful drawings and full specifications were included as part of the quotation. The client added the Cryogenic Expansion Bellows data into their pipe design software and suggested further modifications which were implemented into the Belman Cryogenic Expansion Bellows solution. To verify the design Belman made a stress analysis (FEA) as well as checking for collisions. The Cryogenic Expansion Bellows construction is made according to IGC/DNV criteria and the Cryogenic Expansion Bellows construction was approved by DNV. The solution featured double bellow Gimbal Expansion Joints with ring reinforcement. Due to a high design pressure of 45 barg and large lateral movements highly flexible bellows were required, however, attention also needed to be paid towards maintaining pressure integrity to ensure a long service life and safe operation. With this in mind, Belman designed Ring Reinforced Cryogenic Expansion Bellows with equalizing rings mounted on the convolutions of the flexible multilayer bellows. These rings will reinforce the bellows against internal pressure. By adding moment of inertia to the bellows cross section, the bellows ability to blow out or buckle was counteracted and its stability and pressure integrity enhanced. Due to the media and the design temperature the Cryogenic Expansion Bellows are made entirely from stainless steel 1.4404 (AISI 316L). With the exception of different nominal diameters to fit the piping of the installation point and built in lengths, the Cryogenic Expansion Bellows have the exact same design parameters.

Pressure tested at -165°C
As the Cryogenic Expansion Bellows are designed for an LNG application, they are tested at -165°C and for 66,35 barg. The test was inspected by Notifiable Body (NoBo) DNV. Belman used only DNV approved material for the Cryogenic Expansion Bellows. Along with the Expansion Joints, 3.2 certificates and full documentation was provided. Belman performed pressure, VT, PT and X-ray tests. Belman has the capability to provide many other tests to comply with IGF / IGC regulations under DNV, such as life cycle test, impact test, tensile test, burst test, fatigue test, full x ray, PT, VT among others.

Time is critical
As the LNG carrier was planned for conversion into a FSRU at the shipyard on time delivery was crucial. The Cryogenic Expansion Bellows had to be manufactured, tested and delivered on-site just in time for the planned installation. Delivery just when the client needs is a focal point at Belman and in this case the client benefitted from Belmans ability to deliver the material right when needed. The shipyard could work according to the plan and the project ran smoothly without any unexpected delays.

Deep experience with Cryogenic Expansion Bellows
With considerable experienced in highly customized Expansion Joints, Belman is the go-to company for Expansion Joints for critical installations that require highly engineered solutions with a high level of safety. Belman has a vast experience with Cryogenic Expansion Bellows for LNG as well as Expansion Joints for low temperatures and high pressure. Expansion Joint solutions for applications with such parameters can be seen amongst our latest projects: Latest Projects