How the KOENIG EXPANDER® Works
Sealing Technology
KOENIG EXPANDER® Plug: Best-in-Class in Sealing Technology
The KOENIG-EXPANDER® is the No.1 solution for reliably sealing drill holes in fluid systems. The one-piece, easy-to-install sealing plugs can be integrated into automated manufacturing and are available in a wide range of materials and sizes.
Originally designed for use in hydraulic assemblies, the KOENIG-EXPANDER® is now well established in many industries. As a component in engines, gearboxes and transmissions, suspensions and braking systems, as well as in steering and fuel injection systems, it withstands even extreme loads in the long term.
Push-Style vs. Pull-Style Plugs
There are both push and pull style KOENIG EXPANDER® versions.
The push-style models require a counter-bored hole. The plug is inserted until it reaches the bore, then a ball is pressed into the seated shell, forcing serrated grooves to expand into the base material – forming a secure, metal-to-metal seal.
Pull-style models eliminate the need for a counter-bored hole by using an integrated mandrel to insert the plug into a drilled hole. Since it can be easily aligned, this plug type is well-suited for angled channels. It's also ideal for setups with holes positioned on multiple faces – especially where repositioning the block for proper orientation is a challenge.
KOENIG EXPANDER® Product Overview
MB Series
These push-style Expander plugs work according to the pressure expansion principle, pressing the ball into the expansion sleeve. The MB series plugs are particularly suitable at high pressure (up to 450 bar) and for base materials with low to medium hardness.
Features:
- Operating pressures up to 450 bar/6500 psi
- Large range of sizes available: from ∅ 3 – 22 mm (also available in inch sizes)
- Corrosion-resistant version
- Available in aluminium
- Normal working tolerance 0 -+0,1 mm
- Quick and easy to install
- Purely mechanical seal due to forced interlocking
CV Series
The CV Expander plugs are available in various materials and with different surface treatments, both in metric as well as inch sizes. Like the MB series, they are push-style, achieving anchorage by pressing the ball of the Expander into the sleeve.
Features:
- Operating pressures up to 450 bar/6500 psi
- Large range of sizes available: from ∅ 3 – 22 mm (also available in inch sizes)
- Corrosion-resistant version
- Available in aluminium
- Normal working tolerance 0 -+ 0,1 mm
- Quick and easy to install
- Purely mechanical seal due to forced interlocking
LK Series
The pull-style LK Series KOENIG-EXPANDERS® are ideal for lower pressures (up to 60 bar). Once sufficient force is reached, the expanding element automatically breaks off at the predetermined breaking point.
Features:
- Operating pressures up to 60 bar/850 psi
- Short installation dimensions
- Generous machining tolerances 0 -+0.12 mm
- Direct installation in system bore
- Purely mechanical sealing
- Fast installation using handy processing tools
- Large product range from ∅ 4 - 18 mm
SK Series
The pull-style working principle of the SK series ensures that the expanding element breaks off once the predetermined force has been reached. These Expander plugs are particularly suitable for use in light metals and high-pressure applications (up to 500 bar). They can also be used for bore holes with a smoother surface finish.
Features:
- Operating pressures up to 500 bar/7200 psi
- Short installation dimensions
- Generous machining tolerances 0 -+0.12 mm
- Direct installation in hydraulic bores
- Purely mechanical sealing through forced crimping
- Quick installation using handy processing tools
Installation Equipment
For installing KOENIG-EXPANDERS® of the SK, HK and LK series, there are simple lever shears as well as various hydro-pneumatic hand tools available. The quantity of parts to be processed determines which is the best option for you.
Download More Information
Sealing Technology and Flow Control Catalogue
An overview of our range of sealing technology and flow control solutions.
5.5 MB | pdf
