Rapid installation from just 3 seconds

SImplifying installation through product & tooling innovation

  • Shortened pre-installation process
  • Zero solvents and waste
  • Ergonomic and system linked tooling
  • Single piece mechanical components
Industry applications

Trusted by leading OEM’s around the world

Koenig Expanders and Check Valves have been designed particularly for operational simplicity in installation. With simple hole preparation and a mechanical one-piece design, Expanders reduce waste in-terms of processes, machining and supplementary solvents and adhesives.

The Koenig Expander is installed with repeatability, ease and integrity, vastly reducing preparation, large manned installation lines and supplementary machining and cleaning.

To ensure all Koenig flow control and hole sealing solutions are completely reliable, every batch is performance tested with 100% inspection. With over 5 billion units installed worldwide, failure rates stay below 1PPM. As a safety critical component, Koenig components are 100% traceable.

Aeroplane braking systems deployed when parled for servicing.


Koenig expanders use leading expander technology to completely seal drilled holes without any waste, adhesives, or solvents. Koenig expanders need half as many pre-installation operations as traditional ball and screwed hole sealing methods. With dedicated predesigned tooling and standardised solutions, there is no requirement for large production ancillary equipment and investment.

Expanders come in two types, suited for different applications.


Push type expanders, Series MB and Series CV, are used to seal counterbored holes. Using a setting tool, the ball is pressed into the serrated sleeve, forming a complete metal-to-metal seal. Max. pressure of 450 Bar and sizes from 3 – 22 mm.


Pull type expanders, Series SK and Series LK, are used to seal holes in difficult to access channels at angles or where holes are on different faces and the block cannot be moved. Pull type expanders use a mandrel to insert the plug into the hole and do not require counterbores or secondary machining. As a setting tool is used to pull the expander back into the hole, the plug expands and tightly seals the drilled hole. Max. pressure 500 Bar and sizes from 4 – 20 mm. Using hand held riveter style tools, expanders can be set in fast times and link directly to progressive production or assembly lines.

Close up of a gearbox transmission
Fuel Injection System distributing fuel through nozzles

Accurate FLUID AND GAS control

Koenig check valves and flow restrictors provide reliable and precise control of fluid and gas in high pressure environments. They use the same metal-to-metal sealing technology as Koenig Expanders to prevent side leakage and remain in place in high vibration environments.


Koenig restrictors manage the flow of gas and fluid in deep-hole installations. Made from 300 series stainless steel with a one-piece mechanical design, following the expansion principle, they remain secure and prevent side leakage. For full flow control, the restrictors orifice can be calculated to achieve your desired flow rates.


Koenig ball check valves provide precise flow control with no leakage. Using the SFC Koenig expander technology they reliably regulate the flow of fluids under extreme pressure. Available in a range of sizes and opening pressures, in reverse and forward designs, Koenig stainless steel check valves are control fluid flow in many applications. The encompassed and self contained, one-piece design, facilitates easy installation and dependable performance.


For more information on the Koenig range, to chat about an application or to request an engineer to call or visit, please don’t hesitate to call or fill out the below form.

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