Some pump jobs are simple. Somebody’s basement is flooded, they call up a rental center and the counter person knows exactly what is needed and the homeowner is given the instruction and the problem is solved. Or the job is more complex but the contractor is an experienced professional and knows exactly what he needs, he rents the right machine, takes it to the jobsite and does what he needs to do.
But other pump jobs are considerably more complex, which is why there are rental companies that specialize in them and why some large national rental companies have had so much success with their specialty divisions, because sometimes real professional engineering is required.
Determining the right pump for the job and knowing how to set it up properly takes skill, experience and expertise. Mike Ramos of Xylem says the first item, of course, is an understanding of customer needs, the timing and degree of urgency, followed by the availability and capability of the resource from the customer and the rental company. “After those elements are known, communicating clear expectations for the supplier and the end user, products and personnel can be mobilized to deliver equipment to site for installation and operation,” Ramos says.
The basic questions, Ramos says, are things like flow rates, properties of the fluids to be pumped, distances and elevations.
“Many times the rental company salesperson on point for the project can diagnose the type of pump required,” he says. “In some situations, the pump application is sophisticated enough that the salesperson may need to enlist the support of an application engineer to review the parameters of the project.”
Mike Grant, portable product and rental market manager at Tsurumi Pump, says there are some basic aspects a rental company needs to determine to know where to begin.
“The application could be anything from emptying a swimming pool, construction site de-watering, flooded basement, to simply transferring water from one place to another,” Grant says. “Much can be garnered by asking simply: ‘What is the pump being used for?’ The main intent is to find out if you’ll be pumping clean water or dirty water. Most rental stores rent both engine-driven and electric submersible pumps. Other questions to ask are: What is the power source? Is there electric power available whether permanent or temporary via a generator? How quickly do you need to complete the job?”
“The questions start at topics like what is the application trying to accomplish and what is being pumped,” says Matt Garay, regional product development manager, United Rentals. “They also explore key information about the jobsite including altitude, elevation, proximity of the pump to the source and where discharge will go. We review a series of questions with the customer to understand their needs. This helps us select the rental pump that will operate at the BEP (Best Efficiency Point). We want the pump system to operate issue free for the duration of the project. In providing a pump solution, we can design around the given site parameters. For example, increasing the suction and discharge size of a hose/pipe could allow a pump to operate at the BEP.”
Brian Sell, director product management, Generac Mobile, says basically that a rental company will need to know what is being pumped and whether it is clean water, dirty water or run-off water. “A rental house will also need to know if there is solid material in the water and the size of the solid material,” Sell says. “It is important to ask questions to get a complete understanding of the jobsite and what the pump will be used for to specify the correct system.
“A common mistake that buyers make when purchasing a pump is that they are not familiar with basic pump theory. There are certain laws of physics that come into play, which will limit the performance of pumps: atmospheric pressure at the altitude in which the pump is operating, air and water temperature, size and concentration of particulate matter (solids), and friction caused from hoses.”
Piping is a critically important part of the job, notes Matt Olivieri, product manager – construction, mining, and rental products for Gorman-Rupp Co. The main elements also include the pump or pumps, fittings and accessories, understanding a pump curve and understanding how to calculate total dynamic head.
“The rental company will need to figure out the type of piping they are going to use, whether it is standard suction piping and lay flat discharge piping, to High Density Poly Ethylene (HDPE) piping,” Olivieri says. “They need to know how they are going to route the piping to the end destination. For example, if the piping needs to cross a road, how are they going to do that? There are accessories such as ‘water bridges’ to utilize so that what is being pumped can cross the road without closing the road down.”
The next step is to calculate the friction loss through the piping and any accessories or fittings that will be used on the job. “From there, they also need to know how much flow the customer is wanting,” Olivieri says. “Knowing the flow and head (also known as the condition point), they are able to look at pump curves to see what pump would work for the application.”
The more training the better!
Obviously, a rental company employee, unless they have experience in the pump industry, isn’t likely to begin work at a rental company with this type of knowledge.
“The selection and design of temporary pump installations has historically been a tribal knowledge type of industry,” says Ramos. “Knowledge has been passed down through the generations. Some companies, like Godwin Pumps of America, a Xylem brand, have implemented training programs like Pumps 101, to transfer that knowledge in a systematic, sustainable manner, that allows the rental companies to onboard employees sooner and realize productivity sooner.”
The more training the better, says United Rentals’ Garay. Generac’s Sell says larger rental companies have an engineer or specialist that will “train the trainer” and provide field and service training as well. They typically are involved in larger complex applications or bid spec projects.
“Among the training courses we offer are pump design basics and proper application design,” he says. “We can also train customers on how to determine Net Positive Suction Head available (NPSHa) and Net Positive Suction Head required (NPSHr). NPSHa is a function of the system in which a pump operates, and NPSHr is a function of the pump design. NPSHa must exceed NPSHr for a smooth, trouble-free operating pump system.”
“They must be competent in pump hydraulics to be able to properly size the pump and understand terms such as: Net Positive Suction Head (NPSH), Suction Lift, Discharge Head, and Friction Loss,” says Olivieri. “Knowing these terms and especially the differences in pump hydraulics will help determine the right pump for the application.”
Supporting the customer
Some customers have the internal capability and experience to select, install and operate temporary pumping systems but many rely on the pump company for 100 percent of the support.
“The support can come in many forms – pump selection, system design, hydraulic calculations and a design drawing, delivery and installation, and, in some cases, personnel on site to operate and maintain the system,” says Ramos.
“The best support a great rental company can provide is technical expertise,” says United Rentals’ Garay. “Clients entrust us to design and implement the most efficient pump system for their projects. By doing so, it allows a client to do what they do best: Build, line and refine. Of course, some customers want a turn-key system, and others want a drop of equipment. It really boils down to ability and preference. A great rental company needs to be able to do both in order to meet customers’ expectations.”
Generac’s Sell points out that a lot of end users may have smaller portable pumps in their fleet but may not have much experience with larger pumps. “End users who do not own larger pumps may require assistance as these pumps can be a bit more complex than a smaller portable pump,” he notes. “The larger dry prime pumps have digital controllers and float systems that take some getting used to. It is also important for the rental houses to have the right accessories like hoses, clamps, and strainers in order to offer a seamless experience for the rental user.”
Safety first – hazards are everywhere
There are dangers with all types of equipment and pumps are no different. The machines themselves can cause injury as can the fluids that are being pumped. Accessories include hose and a variety of objects that can cause falls and other mishaps if contractors and site visitors are not aware of them.
“Safety is always first and foremost,” says Xylem’s Ramos. “Every jobsite poses various safety risks to our teams when deploying pumping equipment. A JSA (job safety analysis) or risk assessment must be completed before any work is to begin on a customer site. All job tasks and hazards must be identified and mitigated using the hierarchy of controls. All Xylem employees are required to be trained in specific safety topics initially and re-current throughout the year before being sent to the field. If at any time there is a question or new risk introduced, all employees have the right and authority to stop work.
“Typical hazards that could be encountered and must be mitigated, but are not limited to: slip, trips and falls, overhead hazards when lifting equipment, pinch points (hand safety), arc flash / shock risks with electrical pumps and controllers, ergonomic factors and or confined space hazards.”
“Pressure ratings on flanges and/or piping will need to be addressed depending on how much pressure the pump can build up,” says Gorman Rupp’s Olivieri. “Depending on the pressure produced by the pump, they may need to upgrade their flanges and/or piping to accommodate the higher PSI. Also, if it is a Tier 4 Final engine-driven unit and needs to go into its regeneration process, the rental company needs to know if the application can handle higher flows/pressures downstream without damaging anything and/or overflowing.”
United Rentals’ Garay suggests that all hose, pipe and cable be sorted and in a uniform line to reduce the typical trips and falls that can derail a well-developed job safety analysis. “Noise can be a safety issue,” he says. “Pumps are loud. Proper hearing protection must be worn, even if someone is around a pump for just the typical ‘minute’ to check gauges.
“Water hammer caused by closing a valve during pump system operations can be a safety concern. Pipe, hoses and fittings can move feet in a quick second or burst and severely injure someone standing nearby. Another safety issue is ‘lock out tag out.’ Companies need to secure the equipment from unexpectedly starting up as a result of automatic/remote controls.”
Sell, of Generac, emphasizes the importance of all workers reading and understanding the operator’s manual and all warnings. He also cautions not to underestimate the importance of wearing the proper personal protective equipment on a jobsite to avoid injuries.
“It’s also important not to pump any corrosive or flammable liquids,” he says. “Most pumps cannot be used for these types of applications. This also why it is important for the rental company to ask what the pump is being used for ahead of time.”