Moving liquid uphill or over long distances? A high head pump will push it through.
Standard centrifugal pumps are usually the first choice for transferring liquids from point A to point B. But when those points are far apart, or there’s an elevation change between the pump and the discharge point, a high head pump delivers the pressure necessary to get the liquid where you need it.
A pump expert from United Rentals explains how these pumps work and what applications they’re suited for
What is a high head pump?
A high head centrifugal pump, also called a boost pump, push pump, jet pump or fill pump, is a type of centrifugal pump designed to overcome high resistance using increased pressure. It can push liquid higher into the air than a standard pump. “High head” refers to total dynamic head (TDH), the level of resistance that must be overcome to move a liquid through a system.
“When you talk about a high head, you're talking about a pump that's going to do pressure,” said Corey Randour, branch manager, United Rentals Fluid Solutions. “When you're moving fluid, you’re typically either moving a lot of volume or pushing a lot of pressure. The high head pumps will give you more pressure than volume.”
A pump’s head is measured in feet or meters. This vacuum-assisted, trailer mounted pump, for example, has a TDH of 550 feet.
High head pumps can be powered by diesel or electric, making them suitable for any worksite.
How does a high head pump work?
The way water flows through a garden hose is a good analogy for understanding how a high head pump works. The hose can move a lot of water, but the water doesn’t shoot out very far because it isn’t under much pressure. If you put your thumb over most of the opening, however, you’ll get less water, but the water will travel farther because the buildup of water in the hose creates more pressure.
A high head pump moves liquid with more pressure than a standard centrifugal pump thanks to the horsepower of the engine and the size and shape of the impeller. The sweeping shape of the impeller blades and the larger impeller design allows the pump to create more pressure before the liquid is discharged down the line. The tradeoff is less space for solids: A high-head pump has less solids-handling capability than a trash pump.
High head pump applications
High head pumps are used in many industries and for many applications. Here are some examples.
In the construction industry, a high head centrifugal pump can be used to jet water (pipe it down at high pressure) to drill holes for a wellpoint dewatering system. A high head submersible dewatering pump can be used to pump water out of a deep excavation.
Liquids transfer in the oil and gas industry
High head pumps are used in the oil and gas industry to transfer liquids from low points to high points (such as a mountain top) or from ground level to a high opening in a tank.
Fire suppression in plants
Plants have an extensive system of piping, commonly underground, weaving through multiple buildings. “A high head pump is going to be able to get through all that piping and provide enough water to suppress a fire,” said Randour.
Chemical plants, for example, use high head pumps to scour the inside of tanks. “They act very much like a pressure washer,” Randour explained.
Testing pipe integrity
Pushing water through pipes at high pressure tests their integrity. Construction contractors use high head pumps to test the piping in new buildings. Data center builders use them to check the integrity cooling tower pipes. In pipeline installations, the pumps are used to test new joints.
Shooting water at high pressure through new piping removes construction debris and contaminants.
How to choose a high head pump
There are multiple considerations to take into account when choosing the right high head pump for your application. The key, said Randour, is knowing how much flow you need (what volume you have to move) and the pressure you need to achieve. A host of factors go into calculating both.
Consulting a pump expert is the best way to help ensure you end up with a pump that can do the job.
“There are many specifications we ask for in order to get customers to the right pump,” said Randour. “That’s in part because the spectrum of pumps United Rentals offers is so wide.” The company’s pump fleet includes pumps with pressures from 50 psi to 300 psi and flow rates from 90 gallons per minute (GPM) to 8,500 GPM.
“We make sure the pump is tailored to exactly what the customer needs,” said Randour. That holds true whether the customer is a contractor looking for a pump when their go-to pump can’t handle a particular job or an experienced engineer looking for pumping solutions for a complex setup.
When not to use a high head pump
High head pumps aren’t right for every application.
“It can be dangerous to use a high head pump when a standard pump is called for,” said Randour. “Not only are you likely to have a system failure, you can do a lot of damage.”
Injuries are also possible. “If you try to install a 150 psi high head pump in a system that’s rated for only 20 to 50 psi, you are putting workers at risk,” Randour added.
The pump experts at United Rentals can take the pressure off your pump selection decision by collecting accurate and complete information about the application and pointing you to a pump that will get the job done safely and effectively.