Not only dirt particles but also water droplets have a direct effect on components of the injection system. This is particularly important for modern common rail systems, which place high demands on fuel quality. Fuel pre-filters from MANN+HUMMEL reduce the level of contamination of the fuel with water even before the feed pump in the low-pressure circuit, thus reliably protecting the injection system. MANN+HUMMEL offers also economical, pressure-loss optimized and high-flow inline filters.

Pre-filter series PreLine

Standard fuel pre-filter

Fuel pre-filter as cartridge solution

Technical features

Fuel pre-filters

Volume flow range

50 – 1200 l/h

Water separation

Up to 99 %

Initial filtration efficiency

> 40 % - 85 % @ 4 µm (c)

Service interval

1000 h or 150.000

Operating temperature

-40 °C up to 120 °C

Product benefits

  • Highly efficient protection of the injection system against water and particles
  • Highly efficient MULTIGRADE filter media
  • Unique three-stage water separation
  • High dirt holding capacity
  • Modular system for excellent flexibility


Powerful details

WAVELOCK bayonet lock – evolution of the spin-on filter concept

Spin-on oil filters from MANN+HUMMEL have been proven for years and offer optimum protection. However, the filter change of conventional spin-on filters is power-consuming and only possible with a strap wrench or a comparable special tool. The bayonet lock developed by MANN+HUMMEL for the mounting of spin-on filters sets new standards for easy servicing and reduction of service costs.


The main design of the WAVELOCK system is largely comparable to the conventional spin‑on filter. The fluid to be filtered flows through the filter head axially into the filter and flows through the filter element from the outside to the inside. The cleaned fluid flows out of the filter through its center. The sealing to the environment and between the dirty and clean side of the filter element is respectively made with a radial O-ring. Depending on the respective requirements, the modular design can be used to integrate additional functions such as a filter bypass valve or an anti-drain membrane. The WAVELOCK spin-on filter does not require additional space for fitting or removal.


Cross-section of the WAVELOCK system

Filter head

Dirty side inlet

Clean side outlet

Flow direction

Filter element

Wavelock spin-on filter

Connection of the WAVELOCK spin-on filter to the flange

The key innovation of the WAVELOCK spin-on filter is the design of the connection to the flange on the filter head. A bayonet concept with three bayonet wings was designed to enable a quick and easy service with fitting or removal carried out simply by a 90° rotation. Filter service takes place without the use of special tools, making maintenance and assembly particularly simple and safe. Clearly defined loosening and tightening torques reduce assembly errors.

The sealing between the filter head and the WAVELOCK spin-on filter is made with two radial O-rings. This robust design with pressurized sealing also seals reliably at high pressures and can compensate relative movements in the application. As there is no thread present in the flow area of the fluid, the component cleanliness is considerably increased. Shavings or wear particles from the thread manufacture or fitting process cannot enter the fluid.

Layout and design of the WAVELOCK bayonet lock

Dirty side inlet

Radiale O-ring seal dirty side

Splash guard

Bayonet ring filter head

Bayonet ring wavelock spin-on filter


Radiale O-ring seal clean side

Clean side outlet

Modular filter system

In order to cover a wide range of applications in fuel, oil and hydraulic oil filtration, the integration of the WAVELOCK design into a modular system is currently being implemented. This enables different sizes, diverse filtration requirements and additional functions to be combined in a modular system. The first product family in which the WAVELOCK concept is being implemented is the modular fuel pre-filter portfolio. There are three different filter heads for the complete product range in this size, the standard version, a version with a hand-operated pump and another with an electric fuel pump. The WAVELOCK spin-on filter is available in two lengths. The WAVELOCK spin-on filters are also available with water separation and will be equipped with a variety of filter media. Finally, with the addition of components such as an electric heater or water sensor, the WAVELOCK fuel pre‑filter system is suitable for universal use.


Filter head variants

without hand pump, manual hand pump or electrical hand pump

Spin-on filters

without or with bowl


optional with heater, sensor, water drain plug, WIF-sensor

Advantages of the WAVELOCK system

  • Tool-free and thus fast filter service
  • Combines the simplicity and variability of a spin-on filter with the requirements of modern filter systems
  • Patented bayonet connection as interface between spin-on filter and filter head enables copy protection and prevents the use of inferior filters
  • Increased operational reliability due to radial seals to the environment and between the dirty and clean sides of the filter
  • Improved component cleanliness by eliminating threads to be machined in the fluid area
  • Robust design using established components from spin-on filter technology
  • Modular design covers different sizes and functions
  • Improved total cost of ownership


Contact us!

Personal contact is important for us. You can contact us with your inquiry any time. We are looking forward to your message – by email or telephone.

Further information

Modern engines in commercial vehicles place high demands on diesel fuel filters. MANN+HUMMEL offers efficient water separation and an improved filter head to ensure the required fuel quality.

Read more

MANN+HUMMEL is supplying the oil filter and fuel pre-filter and main filter with numerous integrated functions for the 5.1 and 7.7 liter diesel engines of the Chinese producer Yuchai. This enables MANN+HUMMEL to demonstrate its excellent systems expertise again when it comes to liquid filtration.

Read more


Learn more about technical details, characteristic curves and order numbers in our catalogs, installation and maintenance instructions.