Continuing with the previous article, there are some issues that need to be considered when designing solutions for Vacuum Insulated Piping System for cryogenic applications in the Chip Industry.

Two Types of Vacuum Insulated Piping System

There are two types of Vacuum Insulated Piping System: Static VI System and Dynamic Vacuum Pumping System.

Static VI System means that after each pipe is made in the factory, it is vacuumed to the specified vacuum degree on the pumping unit and sealed. In the field installation and put into use, a certain period of time do not need to be re-evacuated to the site.

The advantage of Static VI System is low maintenance costs. Once the piping system is in service, maintenance is required several years later. This vacuum system is suitable for systems that do not require high cooling requirements and open places for onsite maintenance.

The disadvantage of Static VI System is that vacuum decreases with time. Because all materials release trace gases all the time, which is determined by the physical properties of the material. The material in the jacket of VI Pipe can reduce the amount of gas released by the process, but cannot be completely isolated. This will lead to the vacuum of the sealed vacuum environment, will be lower and lower, vacuum insulation tube will gradually weaken the cooling ability.

Dynamic Vacuum Pumping System means that after the pipe is made and formed, the pipe is still evacuated in the factory according to the process of leak detection, but the vacuum is not sealed before delivery. After the field installation is completed, the vacuum interlayers of all pipes shall be connected into one or more units by stainless steel hoses, and a small dedicated vacuum pump shall be used to vacuum the pipes in the field. Special vacuum pump has an automatic system to monitor the vacuum at any time, and vacuum as needed. The system runs 24 hours a day.

The disadvantage of Dynamic Vacuum Pumping System is that the vacuum needs to be maintained by electricity.

The advantage of Dynamic Vacuum Pumping System is that the vacuum degree is very stable. It is preferentially used in the indoor environment and vacuum performance requirements of very high projects.

Our Dynamic Vacuum Pumping System, the whole mobile integrated special vacuum pump to ensure the equipment to vacuum, convenient and reasonable layout to ensure the effect of the vacuum, quality of the vacuum accessories to ensure the quality of the vacuum.

For the MBE project, because the equipment is in the clean room, and the equipment is running for a long time. Most of the vacuum insulated piping system is in the closed space on the interlayer of the clean room. It is impossible to implement the vacuum maintenance of the piping system in the future. This will have a serious impact on the long-term operation of the system. As a result, the MBE project employs almost all Dynamic Vacuum Pumping System.

Pressure Relief System

The pressure relief system of main line adopts Safety Relief Valve Group. Safety Relief Valve Group is used as a Safety protection system when overpressure, VI Piping cannot be adjusted in normal use

Safety Relief Valve is a key component to ensure that the pipeline system will not be overpressure, safe operation, so it is essential in the pipeline operation. But the safety valve according to the regulation, must be sent to check every year. When one safety valve is used and the other is prepared, when one safety valve is removed, the other safety valve is still in the pipeline system to ensure the normal operation of the pipeline.

The Safety Relief Valve Group contains two DN15 Safety Relief Valves, one for use and one for standby. In normal operation, only one Safety Relief Valves is connected with the VI Piping System and runs normally. The other Safety Relief Valves is disconnected from the inner pipe and can be replaced at any time. The two safety valves are connected and cut off through the side valve switching state.

The Safety Relief Valve Group is equipped with a pressure gauge to check the piping system pressure at any time.

The Safety Relief Valve Group is provided with a discharge valve. It can be used to discharge the air in the pipe when purging, and nitrogen can be discharged when the liquid nitrogen system is running.

HL Cryogenic Equipment

HL Cryogenic Equipment which was founded in 1992 is a brand affiliated to Chengdu Holy Cryogenic Equipment Company in China. HL Cryogenic Equipment is committed to the design and manufacture of the High Vacuum Insulated Cryogenic Piping System and related Support Equipment.

In today’s rapidly changing world, providing advanced technology while maximizing cost savings for customers is a challenging task. For 30 years, HL Cryogenic Equipment Company in almost all cryogenic equipment and industry have a deeper into application scene, has accumulated rich experience and reliable, and continuously explore and strive to keep up with the latest developments in all walks of life, providing customers with new, practical and efficient solutions, make our customers more competitive in the market.

For more information, please visit the official website www.hlcryo.com, or email to info@cdholy.com .