Reader's Response: Draft 2

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 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 operation involving fluid transportation, the submersible pump does pose certain limitations. This includes difficulty in conducting regular maintenance as well as a need for consideration regarding the corrosive effects of fluids on the submersible pump. 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 cost and longer service life.  

Self-priming pumps cost less to maintain because they 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 (Why Choose Self-priming Pumps as an Alternative to Submersible Pumps? | Castle Pumps, n.d.). Furthermore, submersible pumps require cleaning before conducting maintenance as it would be coated in leachate or other unsanitary fluid. Hiking up the cost of maintenance as the resources required to perform maintenance increases as well as reduced operational run-time (Khatami, 2021). 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 it can provide accessibility for maintenance which is crucial to reducing the long-term cost of maintenance. 

Another benefit to using a self-priming pump would be its longer serviceable life due to its lack of exposure to fluid. While the siphoning pipe is exposed to the fluid, the main body and system of the pump is kept out of the fluid. However, submersible pumps are subjected to the effects of the fluid such as corrosion and erosion. Erosion happens when the particles in the fluid constantly flow and rub against a material (Rakibuzzaman et al., 2024). Friction between the particle and material creates an abrasive effect which wears the material over time. On the other hand, corrosion is caused by seawater (Enhancing Submersible Pumps: Maximizing Lifespan and Performance, n.d.). Materials such as cast iron runs a higher risk of getting corroded. Hence, the material of the submersible pump matters greatly to mitigate the adverse effect of the fluid. Yet, all these considerations are impervious for the self-priming pump as it is not subjected to the degrading effects of fluids. Hence to avoid such additional consideration, project managers would prefer self-priming pump over submersible pump.

While the submersible pump is expensive to maintain, it is more cost effective to set up as compared to the self-priming pump. Because of its compact design, the submersible pump is able to fit into narrow environments. On the other hand, a self-priming pump requires a dedicated pump station, where the pump unit is housed. This adds to the initial cost of the self-priming pump. Unlike the self-priming pump, the submersible pump is at an operationally-ready state at the point of deployment. The ease of the submersible pump’s deployment makes it especially useful for flood management. In cases where the project is short-term, providing an entire pump station to facilitate the operation is not cost effective.

While the submersible pump is not ideal for long term projects, it is highly effective for short term operation where most of its weaknesses are not present. Submersible pumps are specialized pumps which work most effectively in the condition that is ideal for it. A project manager would have to study the environments and pick the pump best suited for the environment. In most cases, projects are long and require the pump to work for many years. Hence, self-priming pumps would usually be preferred over submersible pumps.

References Ali Khatami (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/

Enhancing submersible pumps: maximizing lifespan and performance. (n.d.). https://blog.hayespump.com/blog/enhancing-submersible-pumps-maximizing-lifespan-and-performance

Hernandez-Sandoval, J., Gonzalez-Lopez, R., Hernandez-Rodriguez, M., & Guzmán, A. (2015). Localized corrosion in an electrical submergible pump (ESP). Engineering Failure Analysis, 53, 124–131. https://doi.org/10.1016/j.engfailanal.2015.03.021

Rakibuzzaman, M., Kim, H., Suh, S., Islam, M. D., & Zhou, L. (2024). Effects of cavitation and erosion on submersible drainage pumps: A numerical study. AIP Publishing. https://doi.org/10.1063/5.0223126

Waqar. (n.d.). Submersible Pump: Working, Types, Applications, & How To Prime It. Mechanical Boost Website. https://mechanicalboost.com/submersible-pump/

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

Castle Pumps (n.d.)Why choose self-priming pumps as an alternative to submersible pumps?. https://www.castlepumps.com/info-hub/self-priming-vs-submersible/