Pump rentals can mean big business for rental centers. Pump applications can be far reaching … from the general construction dewatering job, to flood control to unique applications in the fishing and recreation industry. These varying applications suggest that rental customers will have different levels of pump knowledge regarding the type of pump needed for a particular job. Rental centers and their customers can choose from a wide range of pumps. Selecting the correct pump for the application is important.
The most common pumps available for rental are trash, dewatering, diaphragm and submersible pumps. Each of these pump styles is designed for different applications. Centrifugal trash and dewatering pumps are very versatile and are among the simplest and most efficient.
Dewatering pumps
Dewatering pumps are relatively inexpensive, but do not contain high quality components. The water being pumped must be relatively clean, containing solids up to 1/4 inch in diameter and less than 10 percent by weight of the water/material being pumped. Benefits of dewatering pumps include high volume flow capabilities and a lightweight, compact design. These pumps are best suited to pump unwanted water from flooded basements, utility vaults, swimming pools, lakes and barge holds. Dewatering pumps can also supply water to rural fire trucks, water trucks and small irrigation projects.
Trash pumps
Trash pumps contain high quality components and are well worth the additional cost. This type of pump is often the preferred choice in the construction industry. These pumps can handle clean, muddy, mucky or sandy water with solids up to 2 inches in diameter (depending on pump size) and between 10 to 25 percent by weight of the water/material being pumped. Applications include pumping unwanted water from excavations, flooded basements, manholes, utility vaults, mining work, swimming pools, lakes and barge holds. The rental industry uses trash pumps because of their reliability and versatility.
The capabilities of trash and dewatering pumps include 25-foot suction lift at sea level, high discharge heads. They are lightweight and portable, are a small investment for large capacity, have few parts and are easy to maintain. Limitations include high water content to move solids. They are not for mud and thick slurries. Dewatering pumps can handle 10 percent solids or less. Trash pumps can handle 10 to 25 percent solids. Applications include clear water, water with algae or suspended clay and silt, abrasive or fast seepage ditch water.
Submersible pumps
Submersible pumps offer contractors versatility on the jobsite. These pumps are primarily for water containing solids up to 1/4 inch in diameter and less than 10 percent by weight of the water/material being pumped. They are relatively inexpensive, can run unattended and are lightweight and quiet. Pumping unwanted water from well casings, tunnels, shafts, flooded basements, manholes, vaults, swimming pools and farm field drainage collection systems are some applications appropriate for submersible pumps. They can also supply water to water fountains, waterfalls and small irrigation projects. Submersible pumps are directly connected to an electric motor and are lowered directly into the liquid to be pumped.
The capabilities of submersible pumps include no suction hose requirement, high discharge heads, a small investment for large capacity, few parts, low repair and service costs, instant priming, runs dry for short time, does not need constant attention and has no lifts to calculate. Limitations are that it must be pulled out for inspection, an electric power source is required and it handles 10 percent solids or less. Applications include water with algae, water with suspended clay, abrasive water, slow seepage ditch water (assuming the pump does not exeed the amount of water coming in or float controls are in place to maintain level).
Diaphragm pumps
Diaphragm pumps are effective in muddy applications and are often used where the content of solids is high and/or a condition of seepage exists. Because of this muddy application, diaphragm pumps are commonly referred to as mud hogs, mud suckers or simply mud pumps. While diaphragm pumps do not pump high volumes for their weight, they are very useful because of their versatility. Diaphragm pumps have the capability of pumping water with greater than 25 percent solids by weight of the water/material being pumped.
Diaphragm pumps do not require a steady flow of water and can handle large amounts of solids. The capabilities of diaphragm pumps include a 25-foot suction lift at sea level, full capacity on each stroke, handles low seepage, keeps pumping in shallow water, pumps mud and large amounts of solids, easy to maintain service valves and diaphragm. Limitations include low discharge head and pressure, small capacity for investment vs. centrifugal models and handling of 25 percent solids and above. Applications include water with algae, water with suspended clay, mud water, silt water, abrasive water, water with high solid content, slow seepage ditch water and septic tank.
Basic pump operating tips
High quality pumps require preventive maintenance, and most of all, proper operation to maintain levels of high performance. There are several basic guidelines that a pump operator can follow to ensure many hours of successful and trouble-free operation.
- Position the pump as close to the source as possible, using as short of a suction hose as possible. The shorter the distance a pump has to move liquid, the higher the volume the pump will deliver. Long hoses produce more friction and ultimately less volume.
- Check the suction hose for leaks and secure all fittings. Most pump failures are due to a faulty suction hose or connections. Even a tiny pinhole on the suction side may cause the pump not to prime.
- Check that the discharge hose is not kinked. If this hose is pinched or clogged, air cannot escape and the pump will not prime.
- Always use reinforced hose on the suction side to avoid collapse.
- Always run the pump at the manufacturer's specified rpm. Running at lower than recommended rpms can decrease pressure head and flow rate.
- Make sure the fitting on the suction hose has a gasket.
- Use the proper strainer to avoid clogging and damage.
- Make sure flapper valves are operational.
- Prime the pump (fill the pump housing with water) before use. Make sure the check-valve is operational and check pump vacuum at suction inlet.
Pumps, whether they are trash, dewatering, submersible or diaphragm, are an integral part of a rental fleet. Understanding applications they are designed for will help rental center operators recommend the right pump for the job.
Mark Conrardy is sales engineering manager for Wacker Corp., Menomonee Falls, Wis.
Thompson Pump
The dependability of the Thompson HT wet prime multi-purpose trash pump can be attributed to its solid cast iron construction. It features cast iron rubber-lined wear plates and dry running abrasion resistant tungsten carbide mechanical seals with viton elastomers. The pump is quick to self-prime and requires little maintenance. Each model includes two or three vane impellers in sizes ranging from 2 to 12 inches with capacities up to 380,000 gph and heads to 120 feet.
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Wacker
Wacker releases three redesigned 2-inch centrifugal trash pumps. The PT 2A weighs 96 pounds, and a 5.5-hp Honda engine powers it. The PT 2V weighs 107 pounds and has a 6-hp Vanguard engine. The PT 2H weighs 131 pounds and offers a 4.6-hp Hatz diesel engine.
Circle 145 on reply card.
ITT Flygt
Designated as models Ready 40, 56 and 90, the small-diameter submersible pumps from ITT Flygt are designed for use by contractors. Weighing 123 (Ready 40 and 56) and 198 pounds (Ready 90) and with a diameter of 11 1/2 (40 and 56) and 14 3/16 inches, the pumps can be transported easily to any site. The high-head models develop up to 240 feet of head, while the high volume model pumps up to 900 gpm. Constructed of an aluminum alloy, the pumps incorporate motor shafts, outer jackets, strainers and fasteners made of stainless steel.
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Giant
The gear end of Giant's industrial pumps were built to last for thousands of hours of operation. From deep-forged crankshafts to bronze connecting rods and high polish finish on solid ceramic plungers, the pumps ensure smooth operation and less wear on fluid end components. With larger surface areas, the pumps not only are quieter but run with greater efficiency and less chance of cavitation.
Circle 147 on reply card.
CH&E
Two self-priming trash pumps join the expanding CH&E dewatering line. These centrifugal trash pumps have several features suitable for long-term trash pumping projects. The new 2- and 3-inch models can be started quickly without the need for manual priming and can handle large solids and other obstacles. Increased durability is the result of specifications, which include a special silicone carbide seal, hi-chrome cast iron impeller and rugged cast iron volute.
Circle 148 on reply card.
Multiquip
Multiquip offers a full range of dewatering pumps designed to meet the needs of professional contractors. The centrifugal pumps are designed to handle all types of clear water applications and have a maximum capacity of 30,000 gph. Trash pumps are available in 2-, 3-, 4- and 6-inch models with a maximum capacity of up to 96,000 gph. The submersible pumps are available in sizes ranging from 1 1/2 to 6 inches and provide high capacities — up to 47,400 gph — with heads up to 138 feet.
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Godwin
Godwin Pumps unveils its new Sub-Prime electric submersible pump GSP models, which feature a top discharge, flow rates to 5,000 gpm and discharge heads to 375 feet. The units, with a slim-line design made for fitting into confined spaces, are designed for large dewatering applications requiring high head or high volume, with single-phase motors to 6 hp and three-phase motors to 80 hp. In addition to high flow capacity and slim design, the pumps feature a cast chromium steel impeller and heavy-duty rubber coated adjustable wear parts. Other features include tandem mechanical seals for dry running and extra protection against leakage, dual phase on selected models for electrical supply flexibility and dual-voltage junction chamber for convenient changeover in the field.
Circle 150 on reply card.
Robin Subaru
The PTV305D diaphragm pump from Robin Subaru is designed for pumping water with heavy debris. It incorporates self-cleaning water flow for rocks and solids. It has a steel roll cage with lift hook and durable neoprene diaphragm and valves.
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John Deere
John Deere's 235 centrifugal pump is designed for controlling flooding in excavations, trenches and pipelines as well as emergency services such as pumping flooded basements or small pools. The sand-cast pump features a 3.5-hp engine with cast-iron cylinder liner for even heat dissipation and long engine life. It also has a 28-foot suction lift at sea level that allows the pumps to be placed farther from the source.
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NAC
NAC centrifugal pumps are available in Honda, Robin or Robin diesel engines that use quality components such as cast iron sleeves, forged steel crankshafts with twin bearings and auto decompressed electronic ignitions. Self-priming, cast aluminum pump heads add to the portability of each unit. Other features that provide extended service life and low maintenance include modular pump design, a durable cast iron volute, three-vane impeller and a long-life mechanical seal.
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Tsurumi
The EPT2 series of pumps from Tsurumi run on heavy-duty Honda gas engines with oil sensors. High chrome impeller, cast iron volute casing plus stainless steel wear plate promise increased durability and decreased maintenance. A durable rolled-steel frame provides maximum protection. Galvanized steel hose couplings promise longer thread life.
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Putzmeister
Specifically engineered to handle difficult jobs extending up to 800 feet, the BSA 2110 HP-D high pressure concrete trailer pump from Putzmeister is powered by a 326-hp turbo-charged Deutz diesel engine. It features 3,190 psi pressure. Additional features include the field proven S-valve, hard-chromed concrete cylinders and smooth free flow hydraulics for more controllable pumping. It's also equipped with a large 21.2-cubic-foot capacity hopper, standard vibrator and central lubrication.
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