Problems with vertical bag pumps

The reason for using this type of pump is surely that the bottom part isn’t suitable for maintenance personnel to enter and carry out repairs. What kind of pump is a vertical cartridge pump, as you mentioned? Is it a suspended pump (VS)?

A type of submersible pump, belonging to the VS6 series; it has an outer casing and is generally used in cryogenic applications

Vaporization: is the process by which a substance changes from a liquid state to a gas state. These include evaporation and boiling. What corresponds to this is liquefaction! Cavitation: Cavitation (cavitation; cavitation erosion) is also known as air erosion or cavity erosion. A phenomenon of cavernous corrosion and damage occurring on the metal surface in contact with the fluid under conditions of high fluid flow and pressure changes. It often occurs in high-speed decompression zones such as at the tips of centrifugal pump blades, where cavitation forms. These cavities are destroyed in high-pressure areas, generating shock pressures that damage the protective layer on the metal surface, thereby accelerating corrosion. The characteristic of cavitation is that many small pitting forms on the metal surface first, which then gradually expand into cavities.

Vertical pumps eliminate the wear caused by the pump shaft and impeller, under the effect of gravity, on the components that come into contact with the pump body! For example, the friction between the impeller mouth ring and the casing mouth ring, as well as the bending of the pump shaft caused by the rotor’s weight! Wait! Furthermore, the lower and more constant underground temperature reduces the pump’s net positive suction head! It’s very suitable for working with hydrocarbon media! Additionally, pumps arranged in this way are also very easy to disassemble and repair! The bearings inside the pump are fluid-lubricated sliding bearings! The axial balance mechanism of multi-stage vertical pumps is also relatively simple!

I agree with you, but vertical pumps are likely to be more expensive than horizontal pumps. In deep pits, can horizontal and vertical pumps be used interchangeably?

In the VS6 pump, the impeller inlet is located at the bottom of the cylinder bag, which is buried underground; therefore, the net positive suction head is equivalent to the height of the cylinder bag added to it. The ordinary horizontal pump OH2, when buried underground, operates on a principle similar to that of the cartridge pump in terms of increasing the net positive suction head; however, due to constraints related to maintenance and electrical zoning requirements (where the underground area is generally classified as Zone 1), it is not usually installed in this manner. Sack pumps can be equipped with multiple stages, allowing them to handle low flow rates at high head pressures – something that conventional centrifugal pumps are unable to do.