Consider silt loads before specifying pumping systems

Press release

The detrimental impact of sediment loads in rivers on the functionality of pumping systems is often overlooked and leads to the premature failure of many abstraction projects for irrigation and other purposes.

Pumping specialist Darren Ward, area manager for KSB Pumps and Valves says sediments, comprising sand, silt, clay and gravel pose a significant challenge to the efficiency and reliability of water abstraction processes and should be carefully studied before undertaking projects.

“The presence of sediments in rivers poses multifaceted challenges for pumping systems, with abrasive particles such as sand and gravel causing wear and tear on critical pump components, notably the impeller and casing. This wear not only compromises pump efficiency but also escalates maintenance requirements and operational costs.

“Fine sediments like silt and clay are identified as stealthy culprits, capable of clogging pump intake screens and filters, thereby obstructing water flow and impeding pump performance. This phenomenon often leads to a cascade of inefficiencies and frequent breakdowns within poorly specified pumping systems.

“Few people realise the impact of sediments on the hydraulic characteristics of pump systems, resulting in reduced efficiency, heightened energy consumption and increased operating costs. The corrosive nature of sediments, containing minerals and chemicals that accelerate the deterioration of pump components worsen the situation necessitating costly replacements and repairs.

“The incorrect specification of pumps, valves, pipes and components unfortunately also have a financial toll with operators grappling with escalated maintenance demands, frequent cleaning requirements and the need for part replacements, all of which strain operational budgets,” he says.

Darren continues that the importance of proactive measures, including the use of abrasion-resistant materials for pumps, installation of sediment filters and adherence to stringent maintenance schedules is paramount. However, the threat of sediment load extends beyond pumps, with pipes and valves within water systems also vulnerable to wear, reduced flow capacity, valve malfunction, corrosion and maintenance nightmares.

“It is always a safe option to make use of an accredited SABI engineer with the skills and credentials to evaluate the requirements and specify a system based on the average and seasonal sediment loads in our waterways,” Darren concludes.

Fast fact

Despite the innocent appearance of sediments in waterways, the free-floating materials have been known to render entire pumping systems inoperable in as little as three months.

Photos supplied.

Relevant Agribook pages include “Irrigation” and “Pumps and generators“.