Gear Pump Operation and Maintenance
PumpScout
Gear pumps are the most common type of positive displacement pump, ideal for transferring high viscosity fluids such as automotive oils, plastics, paint, adhesives, and soaps. They operate by creating suction at the inlet with a rotating assembly of two gears –a drive gear and an idler. Flow is determined by the size of the cavity (volume) between gear teeth, the amount of slippage (reverse flow), and the speed of rotation (rpm) of the gears.
As with any pump, proper operation and regular maintenance are vital to reducing costly pump repairs and maximizing pump efficiency. Below are helpful tips for operating your gear pump and ensuring it achieves a long operating life through regular maintenance.
Gear Pump Operation
– Operate close to the maximum rated speeds. Because gear pumps have poor volumetric efficiency at low speeds and low flow rates, they should be operated as close as possible to their maximum rated speeds for higher production and efficiency.
– Use special materials when pumping liquids with abrasives. A pump’s toothed gear construction allows particles to become trapped in small spaces, accelerating wear and reducing efficiency. If you need to transfer fluid containing abrasives, consider contacting the pump manufacturer to discuss hardened material options.
– Ensure that total life does not exceed 7.5 PSI. A gear pump cannot create a perfect vacuum, necessitating total lift (including pipe friction losses) to be one-half of the atmospheric pressure (approximately 7.5 PSI).
– Avoid low viscosity fluids. Gear pumps (especially internal gear pumps) are designed to handle high viscosity fluids to minimize slip. Pumping low viscosity fluids results in reduced flow rate and efficiency because it ‘slips’ through the tight spaces from the higher-pressure discharge side of the pump to the lower-pressure suction side of the pump.
– Do not run dry. Unlubricated gear teeth will rub together, creating friction and heat as the cogs expand and begin rubbing against the housing. This can destroy the pump, requiring costly repair and downtime.
Gear Pump Maintenance
– Keep maintenance records. One of the most important things you can do to ensure your pump operates smoothly is to keep a detailed record of baseline pump performance, regular maintenance, and any repairs. This will aid you in determining how the pump will operate in the future and the best way to either repair or replace specific parts.
– Check bearings regularly. The bearings are the most important area to maintain because they can cause imbalance if misplaced or defective. Check bearings regularly and replace as necessary by removing the defective bearing with a puller. Excessive noise can be an indication of bearing wear.
– Check gear pump clearance. A new gear pump has .007 to .005 inches of clearance from both the teeth and chamber of the gears. Periodically check for wearing of the teeth by attempting to pass a piece of paper between the clearances. If it passes between the clearances easily, it indicates that the bearings have been worn down and should be replaced.
By following regular maintenance schedules and adhering to proper operation procedures, gear pumps can be an efficient and productive solution to high-viscosity pumping needs.
PumpScout
Related Articles
Cavitation means that cavities are forming in the liquid that we are pumping. When these cavities form at the suction of the pump several things happen all at once. The cavities form for five basic reasons and it is common practice to lump all of them into the general classification of cavitation. This is an error because we will learn that to correct each of these conditions we must understand why they occur and how to fix them.
Cavitation means that cavities are forming in the liquid that we are pumping. When these cavities form at the suction of the pump several things happen all at once. The cavities form for five basic reasons and it is common practice to lump all of them into the general classification of cavitation. This is an error because we will learn that to correct each of these conditions we must understand why they occur and how to fix them.
See More
The article is intended to provide a few tips for blower maintenance to plant maintenance professionals in reducing the downtime and increasing the reliability of blowers. Generally the apparent reasons for blower failure are: Failure of Bearings and High Vibrations
The article is intended to provide a few tips for blower maintenance to plant maintenance professionals in reducing the downtime and increasing the reliability of blowers. Generally the apparent reasons for blower failure are: Failure of Bearings and High Vibrations
See More
A better approach is to measure or deduce shaft RPM and either set unique alarms for different operating conditions or only collect vibration reading if the machine is at the right RPM.Â
A better approach is to measure or deduce shaft RPM and either set unique alarms for different operating conditions or only collect vibration reading if the machine is at the right RPM.Â
See More
Spindles are one of the most expensive and sophisticated rotating components on the planet. They rotate at super high speeds with fits and tolerances 10 to 20 times what is required on other rotating devices, such as pumps or motors. If there ever were machines that needed to communicate their health and activity it would be spindles.
Spindles are one of the most expensive and sophisticated rotating components on the planet. They rotate at super high speeds with fits and tolerances 10 to 20 times what is required on other rotating devices, such as pumps or motors. If there ever were machines that needed to communicate their health and activity it would be spindles.
See More
In this series, we will examine some of the most important water system corrosion mechanisms, with discussion of preventive measures to minimize attack.
In this series, we will examine some of the most important water system corrosion mechanisms, with discussion of preventive measures to minimize attack.
See More
Magnetic drive pumps (also called magdrive pumps) come in three varieties – canned motor pumps, all metal pumps, and plastic lined metal pumps. They are sealless and cannot leak into the environment. Long, repair-free service life depends on recognizing the limitations of these pumps. This article covers issues with using direct mounted, lined magdrive pumps experienced ‘in the field’.Â
Magnetic drive pumps (also called magdrive pumps) come in three varieties – canned motor pumps, all metal pumps, and plastic lined metal pumps. They are sealless and cannot leak into the environment. Long, repair-free service life depends on recognizing the limitations of these pumps. This article covers issues with using direct mounted, lined magdrive pumps experienced ‘in the field’.Â
See More
Electric motor problems. This article presents a basic explanation of electric motor construction and operation along with twelve problems that can be encountered with their use. Most electric motors in industrial equipment are three phase alternating current induction motors. Induction is the creation of an electric current across a gap. Two types of induction motors are commonly used: squirrel-cage and wound- rotor. The names come from the way they are built.
Electric motor problems. This article presents a basic explanation of electric motor construction and operation along with twelve problems that can be encountered with their use. Most electric motors in industrial equipment are three phase alternating current induction motors. Induction is the creation of an electric current across a gap. Two types of induction motors are commonly used: squirrel-cage and wound- rotor. The names come from the way they are built.
See More
