Gear Pump Size Calculator
Find the right pump size quickly with a gear pump size calculator. This tool helps you match flow rate, pressure, and efficiency in seconds to avoid oversizing and reduce energy waste.
Pump Displacement & Performance
How to Use a Gear Pump Size Calculator
Follow these simple steps to determine the correct displacement for your gear pump:
- 1Enter Flow Rate: Input the required flow rate in GPM or LPM. This value depends on your system demand.
- 2Enter Pump Speed: Add the pump speed in RPM. Check your motor or system specifications.
- 3Enter Volumetric Efficiency: Use a typical value between 85% and 95%. New pumps typically operate near 90%.
- 4Enter Pressure (Optional): Input system pressure if required. This helps estimate power and torque needs.
- 5Click Calculate: The calculator will display the pump displacement and estimated performance.
Tip: Always double-check units before calculating.
Gear Pump Size Calculation Guide
Learn how to calculate gear pump size manually using the standard engineering formula.
Formula:
Step-by-Step Example:
Given: Flow Rate = 60 LPM, Pump Speed = 1500 RPM, Efficiency = 90% (0.90)
1. Multiply flow rate by 1000: 60 × 1000 = 60,000
2. Multiply RPM by efficiency: 1500 × 0.90 = 1,350
3. Divide values: 60,000 ÷ 1,350 = 44.44 cc/rev
Result: Required gear pump size = 44.44 cc/rev. Select a pump close to this displacement value.
Gear Pump Size Conversion Chart
Quick reference values for common gear pump sizes assuming 90% efficiency (where applicable):
| Flow Rate (LPM) | RPM | Efficiency | Pump Size (cc/rev) |
|---|---|---|---|
| 20 | 1000 | 0.90 | 22.22 |
| 40 | 1200 | 0.90 | 37.04 |
| 60 | 1500 | 0.90 | 44.44 |
| 80 | 1800 | 0.85 | 52.29 |
| 100 | 2000 | 0.90 | 55.56 |
Frequently Asked Questions (FAQs)
Choosing the right size gear pump requires determining your system's required flow rate (GPM) and maximum operating pressure (PSI). Once you establish these parameters and select an operating RPM, you can calculate the required displacement to ensure the pump meets your exact fluid needs.
The size of a gear pump generally refers to its internal displacement, which is the exact volume of fluid moved per revolution. It may also refer to the physical dimensions of its housing and ports, but displacement in cubic inches or cubic centimeters dictates its performance capacity.
You can calculate the required pump displacement size by rearranging the standard flow formula. Multiply your required GPM by 231 to convert it to cubic inches, then divide that number by your motor's operating RPM. This result gives you the precise displacement size needed for your pump.
Yes, a gear pump can be oversized for a specific system. An oversized pump will deliver a flow rate much higher than necessary, which can lead to excessive fluid velocity, overheating, unnecessary energy consumption, and potential damage to downstream hydraulic components like valves.
If a gear pump is undersized, it will not deliver the sufficient fluid flow rate required for the hydraulic system to operate efficiently. This deficiency causes actuators and motors to move too slowly, severely limiting the overall performance and operational capacity of the machinery.