Add a metal hose at the pump inlet
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Under what conditions is it necessary to install a metal hose at the pump inlet? What is the purpose of adding a metal flexible hose?
For horizontal suction pumps of the ZA or ZE model, when the inlet pipeline is too large and connected horizontally, metal hoses are used to reduce the stress on the pump body. This prevents changes in the alignment between the pump and the motor, effectively reducing pump vibration.
Whether a pump requires a flexible hose depends on various factors related to the pump. 1. Metal hoses should generally be installed at the inlet and outlet of cryopumps, as the temperature difference of the fluid handled is large, resulting in significant expansion and contraction of the pipelines. Therefore, accidents such as pipeline ruptures are likely to occur. 2. In the case of normal-temperature pumps, when the pipelines are short, relatively thick, and have many bends, metal hoses should generally be used, as there are numerous welds under such conditions, which can lead to stress; leaks may also occur at the flange connections or joints.
It should be used in environments with significant temperature and vibration fluctuations, with the aim of preventing damage to the pump body caused by vibration and stress.
In our methanol storage area, there are metal hoses between the large tanks and the pumps, and the temperature difference isn’t significant. Why are hoses used only in this location, while no such hoses are used for the other pumps in the distillation process?
The pump inlet is generally not used; this type of flexible metal hose is mostly applied to the connections at the inlets and outlets of vertical storage tanks with large volumes.
In my personal opinion, ignoring the initial costs, it is advisable to use metal hoses at both the inlet and outlet of all pumps, thereby reducing the impact of pipeline vibrations on the pump’s operation and extending its service life.