How Do Hydraulic Tanks Eliminate Air Contamination?

Posted by McKenzie Thorpe on October 23, 2026 2:03 pm | Comments Off

Your reservoir is more than just a holding space for hydraulic fluid.

“If the reservoir isn’t leaking, all is well, right?”

Actually, the hydraulic tank assembly plays a critical role in removing damaging air contamination from your fluid!

Despite being the central pillar of controlling air contamination, many reservoirs aren’t well-optimized for the job. Even reservoirs that perform adequate deaeration might be secretly weighing down the system and the oil budget.

How can air contamination affect my hydraulic system?

Discussions around contamination usually focus on solid particulates and water. But what happens to a hydraulic system when it becomes contaminated by air?

If not controlled, air contamination targets system components, overall oil condition, and machine efficiency:

Accelerated Oil Aging: Oxygen in the air speeds up the aging of oil.
Varnish / Gel-Like Buildup: Oil aging byproducts like varnish can foul and damage hydraulic system components.
Cavitation: Air bubbles can collapse so violently under high pressure that physical damage occurs.
Microdieseling: Air bubbles may also combust under high pressure, literally burning the surrounding oil & speeding up aging and byproduct formation.
‘Spongy’ Hydraulics: Compressible air can cause delayed responses in the machine’s actions.

Cavitation Damage

How does a hydraulic reservoir influence deaeration?

Unfortunately, it’s impossible to completely eliminate air in a hydraulic system, so best way to handle air in your oil is to influence how the air behaves.

Enabling deaeration involves encouraging any bubbles to coalesce and escape the oil. In a hydraulic system, the hydraulic reservoir is where this deaeration happens.

Ideally, any air bubbles that form in the hydraulic fluid will exit the fluid and disperse into the open headspace of the reservoir.

The key to air removal in the reservoir is reducing fluid turbulence in the reservoir.

Fast, turbulent flow in the reservoir keeps air bubbles circulating and suspended in the fluid for longer. In extreme cases, flow may be high enough that it causes surface disruptions that draw more air into the fluid.

A tank assembly that can reduce the turbulence of flow allows air bubbles to coalesce, rise, and escape from the oil more easily. This can be accomplished with thoughtful tank geometry and carefully selected in-tank filtration.

Eliminating turbulence is also critical for keeping air out of suction lines. The longer air bubbles remain in the reservoir before being drawn into the suction lines, the better their chance of coalescing and escaping the oil. Reducing turbulence is a good way to boost air residence time.

One of the ways that conventional reservoir designs have tried to increase air residence time and combat flow turbulence is by simply making the reservoir bigger.

Increased volume can dampen turbulent flow and increase air residence time…but oversized reservoirs come with some major downsides:

Larger reservoirs require more oil, which drives up oil-related costs.
Bigger, heavier reservoirs increase overall equipment weight and reduce energy efficiency.
With a bigger tank assembly, less space is available for design innovations and other useful features.

How can Tank Optimization and Air Fusion Technology filtration improve my reservoir?

Schroeder Industries’ Tank Optimization uses specialized digital simulations to analyze the existing properties of a tank, identifying inefficiencies in the design. From there, our tank assembly and hydraulic system experts develop a solution that optimizes deaeration and improves overall tank performance.

When paired with purpose-built deaerating filtration, this optimization and redesign process often enables significant reservoir downsizing.

When Tank Optimization meets Air Fusion Technology, reservoir deaeration is maximized.

Tank Optimization analyzes flow, fluid sloshing, structural characteristics, and air residence time—all critical factors in reducing (or potentially worsening) air contamination. Based on the initial analysis, failures of the existing design can be identified and corrected to improve air removal.
Air Fusion Technology is specifically engineered to reduce fluid turbulence and encourage air bubble coalescence. In head-to-head testing with traditional in-tank filtration designs, Air Fusion Technology showcases superior air removal.

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See how these real Schroeder Industries clients achieved significant tank assembly downsizing by combining deaerating filters with Tank Optimization:

Tank Optimization + AFT Produces 77.8% Reservoir Reduction

An OEM producing ride-on snow removal equipment, wanting to be more competitive in the market, sought solutions to improve their hydraulic oil cleanliness and optimize their systems.

By combining Tank Optimization with the advanced deaeration of Air Fusion Technology filtration, Schroeder Industries was able to downsize the reservoir from 9 gallons to 2 gallons, allowing the customer to improve their equipment design and become more competitive!

Here’s how Tank Optimization and Air Fusion Technology helped this customer:

Reservoir Downsized by 7 Gallons and 51lbs (77.8%)

Design Improvements: Runs 2x Longer Than Competitor

Nearly $100 USD Initial Cost Savings Per Unit

View Full Case Study

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Tank Optimization + AFT Nearly Halves Reservoir Volume

An OEM manufacturing mobile seed tending equipment sought to assess the performance of their reservoirs and improve their tank design.

This particular customer was producing their own 12-gallon reservoirs in house. Not only could Tank Optimization improve their reservoir design, but any volume reduction would lessen the materials required for manufacturing.

This Tank Optimization, combined with the fixed head Air Fusion Technology configuration (AFTF), was able to downsize the 12 gallon reservoir by almost half.