Problems with the flexible hoses in storage tanks

Is it true that metal hoses are not necessary when the diameter is less than DN150? To prevent the hose from sinking, it should also be done, presumably. I see that some projects have been done.

It was indeed mentioned during the pressure pipeline audit training

Here is my humble opinion: Based on actual factors such as the properties of the materials, the material of the pipes, the flexibility of the pipes, and the settlement of the tank foundations, it is necessary to conduct a cost-benefit analysis of the possible consequences associated with either using or not using metal hoses, in order to determine whether their use is required. Indeed, there is no one-size-fits-all solution to this issue. 1) As far as I know and from my experience, in some cases where materials are stored, certain foreign companies explicitly prohibit the use of metal hoses, considering them to be weak points that could lead to leaks. 2) In a certain project involving highly corrosive media, metal hoses with a diameter of less than DN50 leaked, while those with a diameter greater than DN80 did not leak. It is likely that the issue lies in the manufacturing process of the suppliers of the smaller-diameter metal hoses (the flow rate factor has been ruled out). Under such circumstances, it is recommended not to use metal hoses for small-diameter pipes. Of course, **the check fails; consider other options.

This post was last edited by Liu Fengrui on 2015-11-30 at 17:34. Metal flexible hoses are generally installed at the inlets and outlets of storage tanks for two purposes: 1) to mitigate the effects of uneven settlement of the tank’s foundation as well as external forces such as earthquakes. 2. Eliminate the effects of stresses generated by the pipeline itself.

Generally, metal flexible hoses are installed at the inlet and outlet of new storage tanks, mainly to eliminate uneven settlement of the tank foundation and the effects of external forces such as earthquakes. For storage tanks that have been in use for over 5 years, since their foundations are already stable, there is no need to use metal hoses.

I’ve never heard of that either. Does it mean that pipes smaller than DN150 have better flexibility and are more resistant to vibrations?

There is no such thing as what the original poster said; generally, metal hoses must be used for the process pipes connected to storage tanks

The audit training for pressure pipelines – I really did mention it

According to the specifications, metal hoses must generally be installed on all process pipelines connected to storage tanks, in order to eliminate stress caused by uneven settlement of the tank foundations or pipeline installation.

Is there such a saying? I don’t think so. The purpose of installing metal flexible hoses is to eliminate stresses caused by settlement or pipeline installation, thereby preventing the pipelines from being torn.