What are the causes of unstable hydraulic pressure?

What Causes Unstable Hydraulic Pressure? ~The True Nature of Fine Contamination Leading to Orifice Blockage and Viscosity Changes~
A common concern heard in the field of hydraulic systems is the problem of pressure instability, such as "pressure is not constant" or "it shifts quickly even after adjustment." While malfunctions of pumps and valves are often suspected, in reality, many of these issues are caused by fine contaminants mixed into the hydraulic fluid. Invisible contamination is undermining the very foundation of pressure control.
■ What Unstable Hydraulic Pressure Means
When pressure fluctuates up and down from the set value, response is delayed and does not follow, or it's unstable against load fluctuations—these phenomena are signs that the internal flow is not proceeding as planned and control is disrupted. Hydraulic control utilizes precise flow paths such as spools, orifices, and flow control valves. If these become "slightly" blocked by fine particles or sludge, the flow rate changes and pressure fluctuates. Even fine particles as small as a few µm can sufficiently cause problems.
■ Scope and Applications
The demand for stable hydraulic pressure is widespread, and the effects of contamination are particularly noticeable in the following equipment:
• Pressure control circuits for molding machines and press machines
• Proportional control systems using servo valves
• Hydraulic units for construction machinery and industrial machinery
• Precision positioning devices for hydraulic cylinders
All of these frequently utilize small-diameter orifices and minute clearances, making them highly susceptible to the effects of fine contamination.
■ Improvement Benefits and Points to Note
By focusing on the root cause of contamination, the following improvement effects can be achieved:
● Benefits of Contamination Removal
• Smoother pressure response and stable set values
• Prevention of orifice blockage and valve sticking
• Hydraulic fluid viscosity maintained constant, improving control reproducibility
• Reduction of sudden stoppages and quality variations
● Points to Note
• Conventional filters cannot completely remove particles smaller than 3µm or emulsified water.
• Water contamination causes viscosity changes and foaming, significantly disrupting pressure control.
• Oxidized sludge is highly viscous, further worsening flow path blockage.
It is important to understand that pressure instability is often caused by "oil contamination" rather than "mechanical failure."
■ Measures to Enhance Pressure Control Accuracy
For pressure stability, maintaining hydraulic fluid cleanliness and viscosity is essential. The following points are particularly effective:
• Fine particle removal: Deeply adsorbs foreign matter smaller than 3µm, preventing orifice blockage.
• Water removal: Dries to ppm levels, suppressing viscosity fluctuations caused by emulsification.
• Oxidized sludge suppression: Decomposes and adsorbs oxides that cause viscosity increase.
• Continuous purification: Introduces a mechanism to prevent dirt accumulation during operation.
As a result, flow rate and pressure stabilize, and control reproducibility and yield improve.
■ Features of Saitama Eco Tech Vietnam's Miracle Boy
"Miracle Boy," offered by Saitama Eco Tech Vietnam, is a high-performance oil purification device that fundamentally resolves the causes of hydraulic pressure instability.
● Main Technical Features
• Deeply adsorbs fine particles smaller than 3µm, preventing orifice blockage.
• Removes water and emulsified water to ppm levels, suppressing viscosity fluctuations.
• Adsorbs oxidized sludge and varnish, preventing oil degradation.
• Retains necessary additives without compromising oil performance.
● Implementation Effects
• Reduced pressure fluctuations and stable control response.
• Significant reduction in valve sticking and poor response.
• Extended oil life, minimizing replacement frequency and waste oil.
• Reduced equipment downtime risk and improved production stability rate.
Unstable hydraulic pressure can be resolved by "oil quality." Miracle Boy constantly maintains oil at new oil levels, maximizing the inherent performance of hydraulic equipment. If you are experiencing problems with unstable hydraulic pressure, please do not hesitate to contact us.