Well Hand Pump Troubleshooting: Technical Specifications and DIY Guide

Well hand pumps are a crucial component of water infrastructure, providing access to clean and reliable water sources, especially in rural and remote areas. However, these pumps can face various technical issues that can impact their performance and longevity. This comprehensive guide delves into the technical specifications and a step-by-step DIY troubleshooting process to help you maintain and optimize the performance of your well hand pump.

Technical Specifications for Well Hand Pump Troubleshooting

Viscosity of Fluid

The performance of well hand pumps is designed for fresh water at room temperature, typically around 20°C (68°F). However, if the fluid’s viscosity is too high, it can significantly impact the pump’s efficiency. For example, if the water temperature drops to 10°C (50°F), the viscosity can increase by up to 30%, leading to a reduction in flow rate of around 15-20% [1]. In such cases, increasing the inlet pipe diameter can help improve the flow rate and overcome the higher viscosity.

Suction Distance

The suction distance, or the vertical distance between the water level and the pump, is a critical factor in well hand pump performance. The recommended suction distance should not exceed 7-10 meters (23-33 feet) to ensure the pump can effectively lift the water [2]. Exceeding this limit can result in reduced flow rate, increased priming effort, and potential damage to the pump components.

Discharge Pipework

The discharge pipework, or the horizontal distance the water travels from the pump to the outlet, also plays a crucial role in the pump’s efficiency. The discharge pipework should be as short as possible to minimize pressure losses and maintain the pump’s flow rate. Longer discharge pipework can lead to a reduction in flow rate of up to 30% [3].

Inlet Pipe Diameter

The inlet pipe diameter should be sufficiently large to allow smooth water flow into the pump. If the inlet pipe diameter is too small, it can create a bottleneck, resulting in reduced flow rate and increased priming effort. As a general guideline, the inlet pipe diameter should be at least 1.25 inches (32 mm) for hand pumps with a flow rate of up to 20 liters per minute (5.3 gallons per minute) [4].

Hand Pump Components

The condition of the hand pump components, such as the cylinder, piston, valves, and seals, is crucial for maintaining optimal performance. Regular inspections and timely replacement of worn or damaged parts can help prevent issues like leaks, reduced flow rate, and premature failure of the pump.

DIY Troubleshooting Guide for Well Hand Pumps

Step 1: Check the Viscosity of the Fluid

Measure the water temperature at the pump inlet. If the temperature is significantly lower than the design temperature of 20°C (68°F), the viscosity may be too high. Consider increasing the inlet pipe diameter to improve the flow rate.

Step 2: Inspect the Suction Distance

Measure the vertical distance between the water level and the pump. Ensure it does not exceed the recommended 7-10 meters (23-33 feet). If the suction distance is too long, consider shortening the suction pipework or using a shallower well.

Step 3: Examine the Discharge Pipework

Inspect the discharge pipework for any blockages, kinks, or restrictions that may be impeding the water flow. Measure the length of the discharge pipework and ensure it is as short as possible to maintain the pump’s efficiency.

Step 4: Check the Inlet Pipe Diameter

Measure the diameter of the inlet pipe and ensure it is at least 1.25 inches (32 mm) for hand pumps with a flow rate of up to 20 liters per minute (5.3 gallons per minute). If the inlet pipe diameter is too small, consider increasing it to improve the water flow.

Step 5: Inspect the Hand Pump Components

Disassemble the hand pump and inspect all the components, including the cylinder, piston, valves, and seals. Look for signs of wear, damage, or corrosion, and replace any worn or damaged parts as necessary.

Step 6: Lubricate the Internal Mechanism

Apply a thin layer of food-grade or silicone-based lubricant to the internal moving parts of the hand pump, such as the piston and cylinder walls. This can help reduce friction, prevent rust, and ensure smooth operation.

Step 7: Drain the Pump after Use

If the hand pump is used with fresh water, make sure to drain the water from the pump after each use. This is especially important for cast iron pumps, as leaving water in the pump can lead to rust and corrosion over time.

Step 8: Keep the Pump in a Dry Place

When the hand pump is not in use, store it in a dry, well-ventilated area to protect it from moisture, dust, and other environmental factors that can cause damage.

By following these technical specifications and DIY troubleshooting steps, you can ensure the optimal performance and longevity of your well hand pump, providing reliable access to clean water for your community.

References:

1. MacAllister, D. J., Nedaw, D., Kebede, S., Mkandawire, T., Makuluni, P., Shaba, C., Okullo, J., Owor, M., Carter, R., Chilton, J., Casey, V., Fallas, H., & MacDonald, A. M. (2022). Contribution of physical factors to handpump borehole functionality in Africa. Science of The Total Environment, 804, 150126.
2. Carter, R., Chilton, J., & MacDonald, A. M. (2015). Understanding handpump sustainability: Determinants of rural water source functionality in the Greater Afram Plains region of Ghana. Sustainability, 7(9), 11699-11719.
3. North Ridge Pumps. (n.d.). Hand Pump Troubleshooting Guide. Retrieved from https://www.northridgepumps.com/article-191_hand-pump-troubleshooting-guide
4. Erpf, K. (2007). Installation, Operation and Maintenance of Handpumps. Rural Water Supply Network.