Centrifugal Pumps

Answers to your most pressing centrifugal pump questions:

• What are Centrifugal Pumps?
• Who Uses Them?
• What Size Do I Need?
• What Types of Seals Should My Pump Have?
• What Maintenance Is Required?
• Which Type of Pump Do I Need?
• What Are the Signs You Need to Repair or Replace Your Pump?

What Are Centrifugal Pumps?

A centrifugal pump is used to transport fluids using energy from an engine or electric motor. The fluid enters the pump inlet, along the horizontal axis and is thrust into the impeller. As the impeller spins and accelerates, the centrifugal force pushes the fluid into a diffuser and then discharges it up out of the pump. A sump pump is an example of a common centrifugal pump.

Who Uses Them?

Centrifugal pumps are the most common type of pump used in these industries:

• Agriculture
• Mining
• Construction
• Utilities/Energy Production
• Municipal (water and waste removal)
• Power Generation Plants
• Petroleum
• Chemical
• Pharmaceutical

Things to Consider When Purchasing

What Size Do I Need?

When selecting a centrifugal pump, you should match the performance of the pump to the needs of your system. An engineer can review the composite curves of different pump styles and sizes. The composite curve of a pump contains its performance specifications, its net positive suction head (NPSH), horsepower, power consumption and many other things necessary to match the proper pump to the proper system.

Talk to our experts to find just the right pump for your needs.

What Type of Seals Should My Pump Have?

Seals are essential because they prevent your pump from leaking when the system is in operation and pressurized. Pumps typically employ single seal and double seal configurations. Single-seal design is more common than double-seal. Seals are typically made from a carbon, carbon composite, or ceramic-based material on a stainless-steel back plate. The single seal is more likely to develop cavities and may become damaged more quickly when used with sticky or abrasive materials. Seal failure is reduced when a pump uses a double-seal design, which consists of two completely independent seals. Fluid between two seals should be closely monitored for discoloration. Any discoloration indicates inner-seal failure and should be addressed immediately.

What Maintenance Is Required?

Like any other type of equipment, pumps need routine maintenance to extend life and prevent downtime that interrupts production. Centrifugal pumps are typically the easiest type to maintain. Routine inspections should be set up according to the guidelines and specifications of your pump. Seals should be checked regularly for damage and signs of wear. Maintenance records and schedules should always be recorded, updated and kept securely. You should check to see if the manufacturer of your pump offers a maintenance program including routine checks and servicing to keep your purchase working properly.

Which Type of Pump Do I Need?

Pumps can be categorized into three general types:

• Axial Flow: Axial flow pumps use an impeller to create pressure on the liquid to be displaced.
• Radial Flow: Radial flow pumps develop pressure through centrifugal force.
• Mixed Flow: Mixed pumps use both centrifugal force and an impeller to create pressure and move fluid.

What Are the Signs You Need to Repair or Replace Your Pump?

Your Pump Won’t Start

If a pump won’t start, it might be because an electrical issue is causing the failure. Check for any loose wiring or disconnections. A blown fuse or tripped circuit may also be the culprit — and both are easily fixed. However, actual motor failure will most definitely require immediate replacement or repair.

Reduced Fluid Flow

There are several conditions that can cause reduced flow:

• Wrong impeller rotation
• Clogged suction
• Worn impeller

Leaking

Any leakage from the pump requires immediate attention. Excessive pressure, heat or corrosion can loosen mechanical joints and create seal failure. Routine maintenance can catch these issues early and make repair much easier and less expensive.

Abnormal Noises

Noises you don’t recognize along with shaking or vibration are most likely signs of seal cavitation. Cavitation can cause shock waves inside the pump and cause damage to the housing and/or the impeller.

Ask our experts for help diagnosing, troubleshooting and repairing pumps.