Quenching is a heat treatment process, where the properties of the metal is changed. It is used to control the normal metallurgical transformation that occurs when metal is cooled, thereby producing the desired hardness. Metal objects are heated in an oven and submerged into an oil bath. The oil is circulated at a specific rate and temperature to achieve the desired results. By quenching the important factors are the properties of the steel, but also the properties of the oil, as this affects the end product.

There are two types of quenching, closed and open. In a closed system, objects are lowered directly from a chamber in a furnace into a quench tank by an elevator or conveyor, while in an open system, the oil bath is a separate process fed from an external conveyor or crane.

During quenching it is important that the oil is clean. This is to achieve cleaner processed parts. Quench oil is contaminated with carbon deposits, particles, sludge and water. The consequences are a lower quality of processed parts, higher production and maintenance costs and longer downtime than absolutely necessary.

Heat treating plant - by Patriot Fluid Power


  • Surface deposits on parts
  • Additional cleaning necessary
  • Varnish and sludge accumulation
  • Longer cooling time required
  • Higher wear on tools
  • Unstable quenching
  • Risk of steam explosions and fires


CC Jensen Oil Cleaning Fine Filters are an effective solution to keeping your quench system clean. Each unit is custom engineered to your application. By installing a CJC™ Offline Oil Filter, the quench process will run more stable with predictable cooling times, and you will avoid the above-mentioned problems. This is why clean oil is important in quenching.

Clean filter media and dirty quench oil filter media - by Patriot Fluid Power

CJC™ Filter Insert – the decisive insert. Our Filter Inserts are comparable to a maze-like and small-pored volume mesh with very small passages. In total the cavity volume amounts to 75% which explains the uniquely high dirt holding capacity.

Large Dirt Holding Capacity throughout the flow path. The microscopic dirt particles deposit in the depth of the filter material. Depending on density and size, several kilograms of particles can be retained until the insert is saturated.

Depth Filtration efficiency depends on the fluid‘s contact time with the filter media. Therefore, CJC™ Filter Inserts are unique with their extremely long filter passages.

Asphaltenes and other oil oxidation products attach to the polar sites of the CJC™ Filter Inserts. The enormous, large inner surface is the reason for the insert‘s very high holding capacity of these contaminations.

CC Jensen quench oil filter - by Patriot Fluid Power

HDU 2X427/81 MZ-E1L1PVT


  • Reducing unplanned down-time (typically by 50-70%)
  • Longer service intervals and lower maintenance costs (typically 50%)
  • Eliminating/reducing costs for oil change
  • Stop carbon, sludge and particle build-up
  • Cleaner parts
  • Stable quench-Steady cooling curve
  • No or less tank cleaning sessions needed
  • Less Manpower required maintaining the quench oil system
  • Reduced risk of oil self-ignition (fire)

Cleaning quench oil makes cleaner parts - by Patriot Fluid Power


Oil test results - by Patriot Fluid Power

Lab test results: The inflow port sample (from reservoir) taken at start-up on 3-01-22 was off the charts dirty and unmeasurable (27/24/20 max reading) and 23 ppm water

The outflow port, sample taken 3/01/22 was at start-up and after a single pass through the filter the ISO Code was 19/18/14 and water 14 ppm (area of new oil)

The inflow port (from reservoir) sample taken on 4-01-22 shows the oil is remaining very clean at 23/21/17 and water 4 ppm.

The outflow sample taken on 4-01-22, ISO Code down to 17/16/12 and water at 8 ppm (cleaner then new oil)

Please Contact Us to have a member of our technical team assist you with your hydraulic oil cleaning needs!