Cryogenic piping design is a complex and important process that requires a series of standards and specifications to be followed to ensure the safety and stability of the piping. Here are some
key design guidelines.
Pipe Material Selection
Material selection for cryogenic pipes is crucial. Common low-temperature materials include austenitic stainless steels, which have excellent mechanical properties and corrosion resistance at low temperatures. At the same time, the amount of linear expansion of the material is also a factor to consider to ensure that the pipe can remain stable in the event of temperature changes.
Pipe Arrangement & Support
Pipes should be arranged in such a way that they are flexible enough to reduce vibration and stress. In the design, the natural compensation of the pipeline should be fully utilized, and when the natural compensation is insufficient, a compensator should be set up. At the same time, the impact of vibration of equipment such as pumps, compressors and exhaust pipes on the pipeline should be avoided, and vibration reduction measures should be taken if necessary. The support of the pipeline should also comply with the relevant standards to ensure stability.
Prevent cold shrinkage
Because cryogenic pipes can shrink during cooling, measures need to be taken in the design to prevent cold shrinkage. For example, setting expansion bends in pipes or using elastic elements, etc.
Drainage and freeze protection
In a low temperature environment, the moisture inside the pipeline is easy to freeze, resulting in pipeline blockage and damage. Therefore, drainage and anti-freeze measures should be considered in the design, such as setting up drainage devices at the low point of the pipeline to ensure that the water inside the pipeline is discharged in time.
Temperature control and stability
The working temperature of cryogenic pipes is usually in a very low range, and the temperature of the pipes must be strictly controlled and stabilized to ensure the normal operation of pipes and accessories. Measures should be taken in the design to control the operating temperature and ensure that the temperature distribution of the pipeline is uniform and stable.
Strength calculation and safety factor
The design of the cryogenic pipeline must meet the strength requirements, including the influence of internal pressure, external load and temperature stress, etc., to ensure that the pipeline has sufficient strength and stiffness under the action of low temperature and external force.
Pipe connection and sealing
The connection and sealing of pipes should be considered in the design to ensure the reliability and tightness of the joints. Common connection methods include welding, threading and flange, etc., and the connection method should be reasonably selected and corresponding sealing measures should be taken.
In addition, the design unit of the cryogenic pipeline shall obtain the corresponding pressure pipeline design qualification license, and the construction and installation unit shall also obtain the corresponding installation qualification license.
Please note that these are only some basic guidelines for cryogenic piping design, and the specific design process requires detailed analysis and calculations based on specific engineering requirements, piping operating conditions, environmental conditions, and relevant standards and specifications. In practice, it is recommended to consult a professional piping design engineer or related institutions to ensure the accuracy and safety of the design.
