Light Equipment Marketplace: Productive pumping
| March 26, 2009
Whether you choose an electric or hydraulic unit, selection and maintenance of your submersible trash pump are critical factors for increasing productivity on the jobsite and extending the longevity of your pump. Making well-informed decisions on application and usage will lower your costs over the life of the unit.
1. Boost your ROI by picking the right pump.
If you perform the same types of dewatering applications over and over, selecting a pump that will offer the most return on investment can be as simple as explaining your jobsite conditions to your sales representative, who will then recommend an appropriate unit. Although you may consider purchasing the largest unit your budget allows, a pump that satisfies most of your needs, or even two smaller pumps to further increase versatility, might be a better choice.
When your site conditions vary – on one job you’re pumping liquid with a lot of solids and one another you’re pumping mainly clear water – you’ll have to more closely evaluate your needs. A pump will provide the greatest return when it is the appropriate size for the job, so select a size that will offer you the most versatility. Some 6-inch pumps, for example, can be equipped with a 4- or 8-inch hose, effectively allowing the unit to function as a 4-, 6- and 8-inch pump. Equipped in this manner, the pump could handle a variety of applications such as construction dewatering, sewer bypass and pumping sludge, slurry and sludge waste.
Your pump should be as simple as possible to maintain. A well-designed pump will allow easy removal and replacement of normal wear parts. Look for a pump with easy-to-access features in a condensed unit that has durable components. Features such as hand knobs or butterfly bolts that can be loosened without tools, sight indicators for visual inspection and fewer moving parts will enable you to service and troubleshoot more easily.
2. Make routine maintenance routine.
Performing preventive maintenance on your submersible trash pump is the best way to preserve your investment and keep your pump operating at peak efficiency. For a guideline to help you determine diesel fuel savings through pump efficiency in 4-, 6-, 8-, 10- and 12-inch hydraulic pumps, visit www.EquipmentWorld.com/pumpcalculator.
Make checklists for daily and 250-hour maintenance – many pump manufacturers can provide one – and use them faithfully. For hydraulic pumps, carefully monitor hydraulic fluid, line fittings and O-rings. On an electric pump monitor voltage, amp draw, run hours and total dynamic head to alert you to potential problems.
If you run your pump as part of a system, conduct a pump system survey to determine the system’s efficiency. Conditions commonly associated with inefficient pump operation include cavitating, badly worn, clogged or misapplied units; impeller and casing wear that increases clearance between fixed and moving parts and excessive wear on rings and bearings.
After you complete a job, run your pump with clean water to remove debris, particularly if you have been pumping material with a high level of sand. If you are located in a cold climate, drain and dry the pump before storing to avoid freezing.
3. Eliminate trouble with troubleshooting.
When the pumpend is in the water, it can be difficult to tell if you have a problem with your submersible trash pump. If you suspect your pump is operating at a reduced capacity, evaluate the unit with a flow meter while the pump is still in the water. The flow meter enables you to confirm the actual head and determine friction losses in the piping system. Use the pump’s performance chart and compare the results to what the pump flow should actually be.
On a hydraulic unit, a worn hydraulic motor, bad hydraulic oil or faulty hydraulic lines can reduce capacity. Check the hydraulic motor case drain flow under load, and ensure the oil cooler is clean and clear. Hydraulic oil should not be discolored, which indicates a loss of viscosity. Even trapped air can compromise a pump’s performance – however, it is also the simplest problem to correct. Just rocking the pumpend will release the air pocket.
On an electric unit, check the voltage and amp readings across each leg of the motor and compare to the amps for the pump, and also check the expected amp draw at the operating point on the performance curve.
A number of problems cannot be determined while the pumpend is in the water and must be found by a visual inspection. For any pump, loose hoses, worn seals, obstructions, a clogged strainer or worn impeller can greatly reduce the pump’s performance. Visit www.equipmentworld.com/pumpguides.