Reader's Response: Draft #3

The article "Submersible Pump: Working, Types, Applications, & How To Prime It" by Waqar (n.d.) introduces the function and design features of the submersible pump. According to Waqar (n.d.), the function of a submersible pump is to transport fluid from one place to another while the pump is fully submerged in the fluid. It achieves this by preventing fluids from entering the motor with its hermetically sealed motor design. As a result of its submersible attribute, the pump does not experience cavitation and has no need for priming. The submersible pump design also features a multistage centrifugal pump. The multistage centrifugal pump consists of a rotating impeller which is driven by the motor. It provides rotational energy to the fluid which is then converted to kinetic energy. Between each impeller is a diffuser, which compresses and increases the pressure energy of the fluid (Waqar, n.d.).  

While the design features of the submersible pump appear enticing for fluid transportation, the submersible pump does pose certain limitations. This includes difficulty in conducting regular maintenance as well as a shorter serviceable life. As such, a more viable option would be self-priming pumps which are favored over submersible pumps by project managers in long-term applications as they offer a reduction in maintenance costs and longer service life.  

One reason why self-priming pumps are preferred in long-term projects is because it cost less to maintain than submersible pumps. Self-priming pumps are more accessible than submersible pumps. In a leachate management facility, submersible pumps are situated under the fluid level, submerged in leachate, during their operating phase. As such, technicians would find it inaccessible to conduct maintenance on the pump unless it is first moved above ground (Khatami, 2021). However, the self-priming pump is stationed above ground where it can be monitored and is accessible for maintenance (Castle Pumps, n.d.). Furthermore, submersible pumps require cleaning before conducting maintenance as they would be coated in leachate and slime (Khatami, 2021). This increases the cost of maintenance as the resources required to perform maintenance increases as well as reduces the operational run-time. As such, the inaccessibility of the submersible pump can increase the cost of maintenance which is unfavorable for long-term projects. Therefore, self-priming pumps are preferred in long-term operations as they can provide accessibility for maintenance which is crucial in reducing the long-term cost of maintenance. 

Another reason why self-priming pumps are preferred over submersible pumps for long-term projects is their longer serviceable life (Martinez-Moore, 2023). According to Castle Pumps (n.d.), self-priming pumps have a lifespan of 20 years while submersible pumps usually last for only 5 years. The difference in serviceable life is largely impacted by the differentiating consequence of the seal’s failure on both pumps. A seal’s failure would likely result in a system failure for the submersible pump. Meanwhile, the seal of the self-priming pump would only be subjected to a replacement should it fail. The root of this differentiating factor is the motor’s location and design. The submersible pump’s motor is built into the pump unit while the self-priming pump’s motor is separate from the pump unit (Castle Pumps, n.d.). Fluid can directly enter the motor should the seal fail in the submersible pump’s design. In contrast, there is no direct exposure to the fluid for the self-priming pump’s motor. Hence, the design of the submersible pump is not as effective at prolonging the serviceability as compared to the self-priming pump.  Project managers would favor self-priming pumps because of their reliability in long-term projects as compared to submersible pumps.

While submersible pumps are expensive to maintain in long-term projects, their compact and portable design allows them to be more user-friendly in household environments. On the other hand, a self-priming pump requires a dedicated pump station, where the pump unit is housed (Gorman-Rupp Pumps, n.d.). This adds to the complexity and resources needed for implementing the self-priming pump. Because of the space efficient quality of submersible pumps, providing both moderate flow rate and portability, it is especially useful for small scale flood management (Raj, 2024). Therefore, in cases where the operation is small scale, the submersible pump is more effective than the self-priming pump. 

To summarize, while the submersible pump is not ideal for long-term projects, it is highly effective for small scale operation where its limitations are less pronounced. Submersible pumps are useful for household use where it can be effectively implemented. However, most commercial projects take considerable time to complete and require the pump to be both reliable and cost-effective. Hence, self-priming pumps would be preferred by project managers over submersible pumps in long-term projects. 

References 

Castle Pumps. (n.d.). Self-priming vs submersible pumps. Castle Pumps. Retrieved from https://www.castlepumps.com/info-hub/self-priming-vs-submersible/?form=MG0AV3   

Khatami, A. (2021, March 1). Landfill leachate removal pumps – Submersible vs. self-priming pumps. SCS Engineers. https://www.scsengineers.com/landfill-leachate-removal-pumps-submersible-vs-self-priming-pumps/

Martinez-Moore, P. (2023, November 09). What are self-priming pumps? Retrieved from https://www.northridgepumps.com/article-89_what-are-self-priming-pumps?form=MG0AV3

Gorman-Rupp Pumps. (n.d.). Of self-priming centrifugal pumps selection & application. https://hayespump.com/wp-content/uploads/Gorman-rupp-choosing-self-priming.pdf?form=MG0AV3

Raj, A. (2024, October 4). The critical role of flood water pumps in modern flood management systems. DAE Pumps. https://www.daepumps.com/resources/flood-water-pumps-modern-flood-management-systems/?form=MG0AV3

Waqar. (n.d.). Submersible pump: Working, types, applications, & how to prime it. Mechanical Boost. https://mechanicalboost.com/submersible-pump/

Waqar. (n.d.). What is centrifugal pump? How does a centrifugal pump work? Mechanical Boost. https://mechanicalboost.com/centrifugal-pump-an-overview/#Centrifugal_Pump_Working