The importance of fuel quality for diesel engines

The latest generation of diesel engines are designed to maximize reliability, power, and efficiency - one of the critical factors in achieving these performance standards is fuel quality.

The most sophisticated diesel engines can fall victim to unexpected and often costly shutdowns due to poor fuel quality. Separator filters are designed to safeguard fuel quality to ensure the reliability of diesel engines used in a variety of applications: power generation, agriculture, construction, transportation, and marine applications.

There are multiple causes that produce contaminants in fuel systems:

  • Water formation due to condensation

  • Water formation due to high humidity 

  • Damaged fuel tanks

  • "Dated" carburetors

  • Fuel obtained from unreliable sources

Water in the fuel can also promote bacterial growth. If this phenomenon goes unchecked, it can cause clogging of filters and injectors, resulting in sudden engine failure.

What are SEPAR filtration systems and how do they work?

Removing contaminants from diesel fuel is the most effective solution to fuel-related problems. Separ systems provide phased filtration to remove water and other contaminants before they can reach the engine, preventing unscheduled downtime or costly repairs. In addition to providing uninterrupted power, this approach has the added benefit of extending the life of engine-mounted filters.

Single and duplex filter assembly

Separ water/fuel separators are available in a variety of models (single and duplex) to suit any application.The ease of installation and maintenance makes them versatile for original equipment and aftermarket installations.

LKF and EVO10 are designed as single and lightweight units, ideal for compact and mobile equipment and transportation.

SWK2000 offers both single and duplex assemblies, which allow switching from one to the other filter without suspension of service.

A duplex assembly is recommended for applications requiring continuous power (UPS, vessels with only one propulsion motor, or generators used for primary power). The secondary filter is therefore a backup.

Sizing by flow rate

Separ offers higher flow rates with lower pressure drops and minimal space requirements. When selecting the filter assembly, its flow rate should be greater than the pump flow rate.

Click here for different filter models SEPAR SWK2000, EVO e LKF.

SEPAR filter models: SWK2000, EVO-10, LKF


The SEPAR SWK2000 series is distinguished by its small physical dimensions in relation to the processed flow rate. The SEPAR SWK2000 is installed between the fuel tank and the engine-mounted fuel pump.
The fuel enters the filter through port A or B. The separation and filtration process is carried out according to a unique and patented concept and consists of 5 filtration steps:


With a maximum flow rate of 158 GPH, the in-line filter offers efficient fuel filtration for construction and agricultural machinery as well as for trucks and emergency generators.

Are you interested in learning more about features, manuals, and certifications of the EVO-10 filter?

See the links below:


The SEPAR LKF filter is ideal for vehicles, boats, agricultural and construction machinery and generators. The standard elements have two different filter media.

Are you interested in learning more about features, manuals, and certifications of the SEPAR LKF filter?

See the links below:

Which filter is best for your needs? SEPAR filters compared


  • Range 79 - 2,060 GPH
  • 5-stage filtration
  • Systems: single and duplex
  • Options: sensor and pressure gauge

The filters feature 99% separation of free water and harmful particles from the fuel through patented 5-stage filtration.

SEPAR Filter EVO-10

  • Up to 158 GPH

  • Unique system

  • Sensor option

  • Lightweight construction

With a maximum flow rate of 158 GPH, the in-line filter is designed to provide efficient fuel filtration for construction and agricultural equipment, as well as truck and standby generator applications.


  • 47 or 126 GPH

  • Unique system

  • Sensor and heater options

  • Nonferrous

The LKF is the ideal filter for vehicles, boats, agricultural and construction machinery, and generators. Standard elements feature two different filter media.