A customer approached Kelair Pumps seeking a reliable solution for pumping lime slurry in a water treatment application. Their primary concern was the risk of damaging their existing helical rotor pump if it ran dry, a real possibility due to the intermittent nature of the pumping process. Additionally, they needed a pump that was both durable and capable of performing consistently under tough conditions while able to handle small solids without the risk of blockage. Given the application involved intermittent pumping and a compressed air supply was available, an air-operated double diaphragm pump was considered to be a suitable option.

Lime slurry, a suspension of calcium hydroxide (Ca(OH)₂) in water, is commonly used in water treatment to adjust pH levels, neutralize acidity, and aid in the removal of impurities like metals and organic compounds. Its primary role is to stabilise water by raising its pH, improving the efficiency of coagulation and flocculation processes to remove suspended solids and contaminants. The abrasive nature of lime slurry, combined with the presence of small solid particles, made selecting the right pump crucial, as traditional pumps risked blockages and damage.

Kelair recommended the Sandpiper 25mm heavy-duty flap valve air-operated double diaphragm pump, which was ideal for this application. The pump's superior solids-handling capability allowed it to pass solids up to 25mm in diameter, compared to standard ball valve diaphragm pumps that can only handle solids up to 6mm. The heavy-duty flap valve design ensured efficient operation, preventing blockages even with small solids in the slurry.

Another key advantage of the Sandpiper pump is its Externally-Serviceable Air Distribution System (ESADS), unique to Sandpiper. This system provides easy access to air system components without the need for full disassembly or pipework removal. ESADS is also lubrication-free and comes with a non-stalling guarantee, ensuring reliability and ease of maintenance.

After installation, the Sandpiper pump exceeded the customer's expectations in both performance and reliability. Its ability to handle lime slurry efficiently, coupled with dry-running tolerance, significantly reduced maintenance concerns. Impressed by the pump’s performance, the customer purchased additional Sandpiper pumps for various solids-handling applications across their operations.

Key Features of the Sandpiper Heavy Duty Metallic Flap Valve range:

• Lightweight and Portable - Weighing as little as 21 kg, allowing for easy transport and manoeuvrability in various applications.
• ESADS+Plus Air Valve – Externally Serviceable Air Distribution System (ESADS) allows for easy maintenance without disassembling the pump, minimising downtime.
• All Bolted Construction – Durable design ensures structural integrity and reliable performance under high pressure conditions.
• Bottom Discharge – Ideal for efficient pumping from difficult or confined spaces.
• Flap Check Valves – Engineered to handle large solids, allowing smooth passage of debris and minimising blockages.
• Durable Diaphragm Connecting Rods – Ensure reliable, consistent diaphragm control for long-term operation with minimal maintenance.
• Solids Range – Capable of handling solids from 1" (25mm) to 3" (75mm), making it ideal for demanding applications involving large debris.
• Superior Dry Prime – Achieves up to 24' (7m) of water suction, ensuring strong priming capabilities even in dry-running conditions.
• Dynamic Manifold Connections – Offers 90° to 180° rotation options, providing flexible installation and easier integration in tight or complex setups.

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