Even when a stainless steel gear pump is properly assembled—with precisely machined unloading grooves, high gear and bearing accuracy, and correct installation—it may still generate excessive noise during operation. This issue is especially common when the gear pump is used in a vacuum oil purifier as the oil discharge pump.
When discharging oil from a vacuum tank, the pump must overcome the suction resistance caused by the vacuum environment. If not handled correctly, this process can lead to significant noise issues. Below are common causes and practical solutions for noise faults in stainless steel gear pumps, particularly in vacuum oil filtration systems.
Common Causes and Solutions for Gear Pump Noise
1. Blockage in the Suction Line or Filter
Problem:
If the suction pipeline or pre-filter is partially or fully blocked, the pump cannot draw sufficient oil. This causes dry friction and cavitation, leading to loud operational noise.
Symptoms:
Visible lack of oil in the suction pipe
The pump may emit a grinding or rattling noise
Decreased flow rate
Solution:
Identify and remove any clogs in the suction line
Clean or replace the blocked filter element
Ensure the suction path is fully open and free of debris
2. Air Ingress in the Suction Line
Problem:
If the suction line allows air to enter, the gear pump will draw in air along with the oil, resulting in cavitation noise.
Symptoms:
Visible air bubbles in the suction line and discharged oil
Irregular pumping sounds
Reduced pump efficiency
Common Leak Points:
Valve joints before the pump
Oil inlet flange seals
The pump’s shaft seals or O-rings
Solution:
Check all suction-side connections and tighten as necessary
Replace worn or damaged seals, including flange gaskets and oil seals
Ensure the shaft seal is properly installed and free of wear
Best Practices for Reducing Gear Pump Noise
Use properly sized suction piping with minimum bends to reduce flow resistance
Avoid excessive vertical lift in suction design, especially in vacuum conditions
Perform regular maintenance on filters and seals
Monitor pump inlet pressure to detect early signs of cavitation
Conclusion
Noise in stainless steel gear pumps, particularly in vacuum oil purifiers, is often the result of suction-side problems such as blockages or air leaks. By carefully inspecting the suction line, filters, and sealing components, and ensuring proper maintenance, these noise issues can be effectively minimized or eliminated.
For long-term reliability and quiet operation, always follow manufacturer recommendations for installation, filtration, and vacuum system integration.