Pumping liquid from the low-level tank
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Compare the advantages and disadvantages of several devices used for pumping liquid at low levels, such as self-priming pumps, submersible pumps, underwater pumps, ordinary centrifugal pumps + foot valves, and ordinary centrifugal pumps + self-priming tanks.
For self-priming pumps, it is necessary to prime the pump before first use or after a long period of disuse. Submersible pumps start with fluid being discharged immediately, and they are more difficult to maintain. Submersible pumps are generally used at temperatures not exceeding 40 degrees. A vacuum tank can convert a regular centrifugal pump into a self-priming pump, with efficiency comparable to that of a regular centrifugal pump. Ordinary centrifugal pumps come with bottom valves, and the pump needs to be filled with fluid each time; this depends mainly on the airtightness of the pump and the pipes.
Self-priming pump: Easy to install and maintain, with stable performance. ★Personal recommendation★ Submersible pump: Difficult to maintain, higher failure rate, but occupies less space. Submersible pump: Suitable for temporary use such as sewage disposal where corrosion is not an issue, and it is inexpensive. Ordinary centrifugal pump + foot valve: The sealing quality of the foot valve largely determines whether this pump is suitable for use; its use over a long period is not recommended. Ordinary centrifugal pump + self-priming tank: It requires more space, but it solves the problem once and for all; this configuration is used in many high-flow pumps for desulfurization applications. ★Personal recommendation★
The advantage of a self-priming pump is that it can be filled once and will then be able to self-priming for the entire lifetime. Self-priming pumps come in horizontal and vertical types; the WFB series of vertical self-priming pumps does not have a mechanical seal, which gives them strong performance and good sewage discharge capabilities. However, their disadvantages are low efficiency, high power consumption, and high energy usage
The FY series of submersible pumps do not have mechanical seals; they offer stable performance. The greater the submersion depth, the higher the price, and the shorter their lifespan is as well. They are also more difficult to maintain, so they are not as good as self-priming pumps
The best value option is the pneumatic diaphragm pump; as long as the flow rate isn’t too high, a pneumatic pump is the ideal choice
This post was last edited by jmdc on 2017-12-23 at 22:04. Why can’t submersible pumps be more widely used? They are so inexpensive, and there are also stainless steel submersible pumps that could completely replace self-priming pumps and submerged pumps. Is it simply because using them makes something seem less professional? The temperature in the tank generally does not exceed 40°C, which is sufficient to meet the cooling requirements of motors. Pneumatic diaphragm pumps are also more expensive than submersible pumps. Is a submersible pump equivalent to a vertical shielded pump?
Submersible pumps are simply of poor quality and not durable; there’s no other reason
For reasons of failure rate, ease of maintenance, and cost, a regular centrifugal pump + self-priming tank is selected.
This leads me to think of another question: when designing a pool, is the depth considered in relation to the type of pump that will be used? Otherwise, why is the depth of most pools around 4 or 5 meters? Pumps of the usual kind cannot draw water from pools that are too deep. If a greater depth is required, then the pool is usually designed to be half its depth above ground level and half below. If it needs to be extremely deep, then submersible pumps are probably the only option. Submersible pumps can reach depths that other types of pumps simply cannot achieve. I’m referring to deep well submersible pumps