Metal flexible hoses and expansion joints
Thread Content
At what diameter does a pipeline require an expansion joint instead of a metal hose?
The selection of flexible hoses and expansion joints is independent of the pipe diameter.
In my personal understanding, for those who are not in the chemical industry: an expansion joint is used in pipes that expand and contract due to temperature changes, for example, at the point where the exhaust outlet of a generator connects to the exhaust pipe； Metal hoses are used in moving parts, such as hydraulic lifting positions, where rigid pipes are difficult to connect.
I have seen expansion joints used when the diameter of the inlet and outlet pipes of storage tanks is large; I couldn’t find any specific specifications for this.
This can also be distinguished, and it seems that the diameter of the inlet and outlet pipes of the storage tank can also be used for differentiation, but I haven’t found the specific specifications yet.
Depending on the equipment, it is usually the vibration of the equipment or deformation that occurs after heating, for which expansion joints are used. Expansion joints are generally not long in length and are designed for long-term fixed use. The hose definitely looks temporary.
The diameters of the inlet and outlet pipes of the storage tank vary; the selection of metal hoses and expansion joints is not determined by the pipe diameter. Metal hoses are generally used at the inlet and outlet of the storage tank to compensate for the height differences in the pipes caused by the settlement of the tank. Expansion joints primarily serve as compensation devices for the thermal expansion and contraction of pipelines, and they are capable of withstanding the thermal stress in the pipelines as well as the vibrations caused by pulses within the system.
You can refer to the discussions in these posts: For connections on storage tanks with a DN300 diameter or larger, should you choose hoses or expansion joints to prevent settlement? https://bbs.hcbbs.com/thread-1963710-1-1.html (Source: Haichuan Chemical Industry Forum) Differences between metal hoses and expansion joints https://bbs.hcbbs.com/thread-1385122-1-1.html (Source: Haichuan Chemical Industry Forum) Applications of metal hoses and expansion joints in process pipelines https://bbs.hcbbs.com/thread-1062735-1-1.html (Source: Haichuan Chemical Industry Forum)
In which specific standard can this be found?