Key structural design considerations for low-temperature pressure vessels

Low-temperature pressure vessels operate under extreme conditions where thermal stress, material brittleness, and structural integrity are critical concerns. To ensure safety, reliability, and long-term performance, specific structural design principles must be followed.

1.Simplified Structure and Uniform Material Selection

The structure should be as simple as possible to minimize constraints and reduce unnecessary additional stresses.

Sudden temperature variations should be avoided, as they can cause thermal stress concentration.

Consistent material selection is essential to prevent differential expansion and contraction, which can lead to structural failure.

stainless steel pressure vessels

2.Avoiding Abrupt Structural Changes

Sudden changes in structural shape should be minimized to reduce localized stress concentration.

High local stress areas are the primary cause of crack initiation and propagation in low-temperature applications.

3.Smooth Transition at Pipe-to-Shell Welds

The fillet weld at the nozzle-to-shell connection should have a smooth concave transition to improve structural integrity.

The inner wall of the nozzle end should be rounded to prevent stress concentration and enhance fatigue resistance.

4.Reinforcement of Nozzle Connections

Integral reinforcement or thick-walled pipes should be used whenever possible to enhance nozzle strength.

If a reinforcement pad is used, it must be a full-penetration welded structure with smooth weld transitions to reduce stress concentration.

5.Proper Welding of Supports to the Shell

Support structures should be welded to the shell with reinforcement pads to distribute stress more evenly and prevent local weakening of the vessel wall.

The structural design of low-temperature pressure vessels must prioritize simplicity, stress reduction, and smooth transitions to ensure safety and durability under extreme conditions. By eliminating stress concentration points and ensuring proper reinforcement, these design principles enhance operational reliability and longevity.

At Haihao Group, we specialize in customized cryogenic pressure vessel components, following international standards and best engineering practices. Contact us for expert solutions in low-temperature pressure vessel design. Email:sales@haihaogroup.com