In The Renter's Box
Tips for How to Rent a Portable Pump
By Stephanie Morgan
Picture yourself on a fresh Spring day heading off toward the batter’s box for some pre-season batting practice. Are you using your own bat or did you just pick one that was leaning against the fence? Borrowing allows selectivity on size and performance whereas ownership implies a more rigorous selection process, considering factors such as manufacturer, weight distribution, etc. And the same is true for portable pump usage.
If you do not own your own equipment and are facing an emergency, perhaps you only have access to what is in the yard at your local rental facility. But, if you have the time to specify a job, there are many variables that you can and should consider.
In a broad sense, you will require pumps for light-duty, short-term pumping and heavy-duty, higher-volume and potentially continuous pumping. Consequently, pump sizes and categories vary drastically based on which application category you need to address.
In both light-duty and heavy-duty pumping, general dewatering pumps are designed primarily for horizontal pumping or product transfer. Pumping vertically against gravity resistance or into a pipeline under pressure requires a much stronger and more expensive type of pump.
Creating the Lineup
In the age-old struggle of rental vs. purchase, one thing is clear — pumps are not one-size-fits-all pieces of equipment. To determine whether to rent or buy, you must first establish the scope of your pumping application and the probability of permanent or recurring dewatering.
 Generally speaking, light-duty pumps are typically purchased, while heavy-duty pumps are rented. Light-duty, gasoline-powered pumps can be purchased for around $1,500 for a 3-in. trash pump. A 6-in., diesel-powered, trailer-mounted pump may list for close to $30,000, which is why rental is an attractive option for heavy-duty pumping applications. Some contractors may find continuous use for a 6-in. portable (trailer-mounted) or permanent (skid-mounted) basic trash pump and will make the investment in purchasing a larger unit.
When considering whether to rent or buy a pump, remember that a full pumping system includes accessories such as suction hoses, screens, discharge hoses, pipes and fittings. The amount of accessories will determine the final pricing. Similarly, the actual pump rental is only a portion of the total cost.
For example, a 10 ft excavation for a manhole installation that needed to move 250 gallons per minute (gpm) of water 100 ft downstream would call for the rental or purchase of a 3-in., gasoline-powered, wet-priming trash pump with 20 ft of suction hose and another 100 ft of discharge hose. If this is regular work, you might purchase the pump and hose and could operate this system in similar applications with little or no assistance.
However, more complicated applications such as sewer bypass systems require the input of a pump specialist. For example, a temporary bypass system capable of handling flows from 1,875 gpm at 168 ft of total dynamic head (tdh) to 3,000 gpm at 120 ft of tdh could require as many as four pumps (two electric and two diesel), two variable frequency drives (vfd) incorporating level transducers and programmable logic controllers (plc) to automatically control the electric pumps, two level transducers to automatically control the diesel pumps and perhaps an auto dialer in the event of an emergency.
In addition, this system may require varying lengths and diameters of suction and discharge hose and piping, adapters, elbows, check valves, a discharge manifold, combo vents, a flanged reducer and ball valve. It is likely that you would team with a pump specialist to size this job, deliver the pumping solution and monitor the pump performance. In this case, you may elect to purchase one pump that you use most commonly, but it is more likely that you would rent this type of system.
Generally speaking, pump rentals follow the same pricing structure that general rental equipment uses for daily, weekly and monthly rentals.
Scouting Report
When shopping for a pump, there are several key indicators of potential return on investment. For example:
Experience and Aptitude of Staff — Whether visiting a manufacturer’s store or a general rental store, the first question you should expect to hear from a pumping specialist should be: “What are you trying to do?” Unless absolutely sure of what you are pumping and what you need, you should rely on the expertise of a pumping specialist. Since large pumps are high capital investments and all pumps can cavitate when misapplied, you need to make sure that the application not only meets the needs of your job, but also falls within the capabilities of the pumping system. If the application extends beyond simple dewatering, be sure to talk to someone who understands not only pumping terminology, such as tdh, gpm, net positive suction head (npsh), horsepower (hp), but also the equipment they have in their yard and its ability to efficiently and reliably meet the needs of the task at-hand. Simply stated, if you try to rent or buy a pump and the representative does not know how the pump works, keep looking.
Availability of Equipment — From light-duty to heavy-duty and everything in between, you will undoubtedly need a variety of pump sizes to meet your dewatering needs. Pumps are available with all types of power sources, and you may need to consider something outside of the standard, diesel or gasoline engine such as natural gas, electric or hydraulic submersibles. In addition, you will need access to hose, pipe, fittings, valves and floats to complete your pumping solution.
Appearance of Store and Equipment — You only get one first impression, so do not ignore your initial reaction to your local store. Evaluate the condition of the yard, noting both the organization and condition of equipment. Keep in mind that how your rental or purchase source cares for its equipment may be a reflection of its potential functionality (or lack thereof). If equipment is poorly managed and maintained, it likely has a greater risk of failure and may reflect improper staffing and perhaps delayed emergency response.
Proximity — You know what they say about the best laid plans, but how often do you think you have everything you need, only to find you are missing something. If you are operating a pump at a relatively remote location, keep in mind accessibility to parts and service from either the closest store or via
direct shipment.
Accessibility — While being close to the equipment shop is definitely an advantage, it is of little consequence if the store has 8 a.m. to 5 p.m. business hours. It is relatively easy to plan a project; however, when was the last time you knew when an emergency would occur? Find a vendor who offers 24 hour service.
Post-Pump Wrap-Up
 There are many variables to consider when selecting pumping equipment. On paper, rental companies often have a slim margin of differentiation between the equipment they offer. The difference lies in the application of the equipment, which, in addition to those things previously mentioned, includes the material being pumped, the jobsite location and the need for monitoring. Pump suppliers go to great lengths to make their equipment easy to use; however, sizing, installing and operating major pumping equipment relies heavily on the attention to detail and experience of the rental company.
You could do all of the research in the world to get the best bat and still strike out. Similarly, you don’t want to get the jobsite and find out that you are drowning in a bad pump purchase. It just goes to show that equipment is only as good as how it is put to use. Do not be afraid to get the help you need to get the right equipment to do any dewatering job right.
Stephanie Morgan is a technical writer for Godwin Pumps, Bridgeport, N.J. |
