Gear Pump Selection Guide

The working principle of gear pumps is based on the positive displacement principle, which moves the fluid through the meshing of two gears. The gears are usually made of PEEK, Hastelloy, etc. and are located in a sealed housing to prevent leakage.

The gears are arranged in such a way that they rotate in opposite directions and mesh with each other, forming a sealed cavity between them. As the gears rotate, they trap a certain amount of fluid between them and pass it through the pump. The fluid is then forced out of the pump through the outlet.

Gear pumps can be divided into several types based on the design and application. Some of the most common types of gear pumps include:

External gear pumps: The gears of external gear pumps are located outside the pump housing. They are usually used for low viscosity fluids and are available in single and dual gear configurations.
Internal gear pumps: The gears of internal gear pumps are located inside the pump housing. They are usually used for high viscosity fluids and are available in single and dual gear configurations.
Spur gear pumps: The gears of spur gear pumps are of spur gear design. They are usually used for low to medium viscosity fluids and are available in single and dual gear configurations.
Helical gear pumps: The gears of helical gear pumps are of helical gear design. They are typically used for high viscosity fluids and are available in single and double gear configurations.
Herringbone gear pumps: The gears of herringbone gear pumps are of a herringbone gear design. They are typically used for high viscosity fluids and are available in single and double row configurations.
Worm gear pumps: Worm gear pumps use a worm gear design and are typically used for high viscosity fluids and low flow rates.
Screw pumps: Screw pumps use a gear design and are typically used for high viscosity fluids, low flow rates, and high pressure applications.
It is important to note that the above classifications are general and there are different variations and designs within each category to suit specific applications.

When selecting a gear pump, the following guidelines should be considered:

• Required flow: The flow rate required for the application will determine the size and type of gear pump required.
• Fluid viscosity: The viscosity of the fluid being pumped will determine the type of gear pump required. For example, a high viscosity fluid will require a gear pump with larger gear sizes and lower speeds.
• Pressure requirements: The pressure required for the application will determine the type of gear pump required. For example, a high pressure application will require a gear pump with a higher pressure rating.
• Compatibility with materials: The gear pump should be compatible with the materials used in the application, such as the fluid being pumped and any seals or gaskets used. Typically, internal gears are made of stainless steel, PEEK, PTFE, etc. It is also important to ensure that the gear pump is compatible with the materials used in the application, such as the fluid being pumped and any seals or gaskets used.
• Fluid temperature requirements: The gear pump should operate within the rated temperature limits. Excessively high fluid temperatures can damage the pump and the internal gears.
• Cleanliness requirements: The gear pump should meet any cleanliness requirements of the application, such as being able to operate in a sterile environment.
• Life cycle cost: The gear pump should have a reasonable life cycle cost, considering factors such as initial cost, energy consumption, maintenance costs, etc.
• Noise level: The gear pump’s noise level should meet the requirements of the application, especially when the gear pump is installed in a noise-sensitive environment.
• Power supply: The gear pump should be compatible with the available power supply and should meet the voltage, current, and frequency requirements.
• Reliability and maintenance: The gear pump should have a good record of reliability and easy maintenance.
• Quality of the manufacturer: It is always recommended to choose a reputable manufacturer with a good record of producing quality gear pumps.