Winter technically doesn’t begin until late December in the Northern Hemisphere, but cold temperatures are already setting in. Work carries on regardless of the chilly weather, but for those operating in the extreme cold, there are some important considerations when it comes to your equipment.

Winter Is Coming, Is Your Equipment Ready?

When dealing with fluid powered equipment—like hydraulic-powered machines and diesel-powered engines—cold temperatures can be detrimental to your equipment longevity and performance. Let’s explore how cold impacts hydraulic fluid and diesel fuel, and what you can do to keep your business running hot:


1. Bypass Blues: Hydraulic Cold Start Conditions

The most consequential effect of cold temperatures on hydraulic fluid is the increase in fluid viscosity.

As the fluid thickens in low temperatures, its ability to freely flow is reduced, resulting in higher differential pressure upstream of the filter. This means that until the machine warms up and the fluid viscosity is lowered, the machine may enter bypass—where the fluid passes around the filter element. The conditions that cause machines to go into bypass due to higher fluid viscosity are commonly known as cold start conditions.

If the fluid is bypassing your filter and filter element, that means that unfiltered fluid is entering your system, putting critical components at risk!

Most filters on the market position the bypass at the bottom of the filter, where contamination settles as the machine sits idle. This means that when the machine goes into bypass, all that contamination is pushed straight into the hydraulic lines. Until the machine reaches sufficient temperatures and exits bypass, allowing your filtration to kick in, the contaminants will flow through the system and cause wear and tear.

Choosing the right filter can help protect your equipment when it inevitably enters bypass due to cold conditions. With the risks of contamination through the bypass in mind, Schroeder has designed filters that protect your equipment in cold start conditions, including:

QF5i with Ferrous Contamination Protection


Ferrous, metallic particulates are among the most damaging types of contamination.

Designed for added protection in cold start conditions, the QF5i includes a magnetic filter rod suspended within the coreless element configuration.

This ensures that even while the equipment is in bypass, damaging metallic particulates accumulate on the rod rather than flushing into the hydraulic system.




GPT Engineered for Bypass Protection


The key to the GPT’s effectiveness is its unique bypass placement.

Unlike other filters on the market, the GPT includes its bypass in the top of the filter within the diverter cap.

During cold start conditions when a machine enters bypass, loose contaminants that have settled into the bottom of the GPT are isolated below the bypass and are not pulled into the hydraulic lines.

When the fluid reaches adequate temperature and normal filtration resumes, those contaminants are then contained safely within the filter element.





Also Consider: Hydraulic Tank Optimization


Tank Optimization is the process of maximizing volume utilization and reducing fluid velocity in a hydraulic reservoir in order to create the most efficient tank assembly possible.

Tank Optimization has many benefits, such as reducing fluid costs and increasing available machine space. It can also improve the efficiency of equipment in cold conditions.

  • With less fluid in the system and improved flow efficiency, the fluid warmup window is reduced, as fluid can reach operating temperature faster.
  • When the desired fluid temperature is reached more quickly, that means less time is spent in bypass, which reduces risk of contaminant exposure and lets you get to work faster.


2. De-aeration Diminished: Increased Air Contamination

When the viscosity of hydraulic fluid increases, it also reduces the fluid’s ability to de-aerate. Thicker fluid means that air bubbles are less able to coalesce, rise, and exit the hydraulic fluid, leaving an increased amount of gas suspended in the fluid. When the system restarts, that suspended air will flow through the hydraulic system and even expand as the fluid temperature rises.

Air contamination has several negative effects on equipment performance and longevity:

  • Gaseous cavitation, which occurs as air bubbles coalesce, grow, and collapse within the hydraulic circuit. This can cause jarring noises and potentially damage the internal components.
  • Unlike fluid, gas can be compressed. Too much air in the hydraulic system can cause delayed reactions in the hydraulic system rather than instant movement, sometimes referred to as a ‘spongy’ feeling in the hydraulics. This results in system performance that is at best inefficient and at worst unpredictable or even dangerous to bystanders and workers.
  • Air contamination also accelerates the oxidation of hydraulic fluid. When oxygen reacts with hydraulic fluid, a sludgy byproduct known as varnish is created. Excess varnish not only decreases the life of the hydraulic fluid, but can build up on internal components, causing blocked return lines, stuck valves, and other serious problems.

Deaeration occurs in the hydraulic reservoir, so ensuring you have the most effective de-aerating in-tank filtration on the market can help prevent air-related issues in cold conditions!

Air Fusion Technology (AFT) Filtration


Air Fusion Technology is thoughtfully engineered for optimal deaeration, removing 20% more air on the first cycle than standard in-tank filters!

The anatomy of the AFT filter includes several key features that enable its exceptional de-aerating performance:


  • The AFT’s specialized bypass valve de-aerates fluid even during bypass, which is especially useful in cold start conditions.
  • The patent-pending endcap design ensures bypass flow that enters the top of the element can still de-aerate.
  • The de-aeration diffuser shroud decreases fluid turbidity and increases bubble coalescence which improves de-aeration
  • The flow distribution cone redirects fluid towards the top of the reservoir, allowing more gas to escape the hydraulic fluid



Deaeration-Optimized, Cold-Resistant Rotomolded TNK


These rotomolded reservoirs combine beautifully with AFT filtration for improved de-aeration!

The TNK series of reservoirs are ultra light yet exceptionally durable, with internal baffling engineered for reduced fluid turbidity and improved de-aeration.

TNK reservoirs can also tough out temperature extremes, including conditions as cold as -40°F (-40°C) while withstanding heavy impacts and rugged working conditions. See one in action below!





3. Frigid Fuel: Paraffin Pile-Up

Paraffin is a type of petroleum-based wax, commonly used in cosmetics, candles, and industrial applications.

As it happens, there’s also paraffin in your diesel.

Diesel fuel contains molecules of dissolved paraffin, and depending on the blend of fuel, there may be more or less paraffin in the mix.

In warm temperatures, the paraffin stays dissolved, with little impact on the fuel system.

However, when temperatures drop, the paraffin begins crystallizing into a solid, which is known as diesel ‘gelling’. As these paraffin crystals begin forming, they can accumulate on dispensing filters and primary onboard filters, causing several potentially serious issues: