AIRflex® Straight Conduit Compression Fittings (LKI & USK)
AIRflex® straight conduit compression fittings are designed for use with AIRflex spiral PVC and polyurethane conduits. These fittings provide secure conduit termination using compression-style mounting and are available in both Metric and PG thread configurations.
Two fitting designs are available to support different installation and motion requirements:
LKI swivel-thread compression fitting
USK traditional compression fitting with locking pressure nut
Both fittings are rated IP54 when installed in accordance with product specifications.
AIRflex® conduits and compression fittings are supplied by IBIS Electro-Products Corp to support reliable spiral conduit installations across industrial and equipment applications.
Understanding the Two AIRflex® Straight Conduit Fitting Designs
LKI Swivel-Thread Compression Fitting
The LKI fitting incorporates a built-in ferrule and is installed by pushing and twisting the fitting into the conduit while following the spiral profile of the conduit wall.
Once mounted onto the conduit, the threaded interface remains free to rotate independently of the conduit body. This swivel-thread design allows the conduit to rotate on axis after panel or device installation.
This feature helps minimize torsional stress on the conduit in applications involving multi-axis movement, vibration, or rotational motion. By allowing controlled rotational movement, the LKI fitting reduces the risk of conduit deformation, over-twisting, and mechanical damage.
Ingress Protection: IP54
USK Compression Fitting (Fixed Lock Design)
The USK fitting is a traditional compression-style fitting manufactured from polypropylene (PP). It uses a separate ferrule and locking pressure nut to secure the conduit.
Installation involves:
Sliding the locking pressure nut onto the conduit
Inserting and twisting the ferrule into the conduit
Pressing the fitting body onto the ferrule/conduit assembly
Tightening the locking nut to compress the ferrule into the conduit
Once installed, the conduit is rigidly fixed to the fitting and cannot rotate.
This design is well suited for static, fixed installations where conduit movement or rotation is not expected.
Ingress Protection: IP54
Selecting the Right Fitting for Your Application
The choice between LKI and USK depends on whether rotational movement or vibration is present in the application.
Choose LKI When:
The conduit is subject to multi-axis motion
Equipment rotates or oscillates
Vibration is present
Torsional stress must be minimized
Long-term conduit integrity is critical
Choose USK When:
The installation is static
The conduit will not rotate or flex repeatedly
A traditional compression lock is preferred
The installation environment is fixed and stable
Applications for AIRflex® Straight Compression Fittings
Dynamic Motion Applications (LKI Recommended)
Moving equipment and articulated systems
Robotics and automated machinery
Rotating camera systems
Motor-driven equipment subject to vibration
Static Installations (USK Suitable)
Fixed electrical enclosures
Security camera conduit runs (non-moving mounts)
Stationary machine installations
Permanent wiring installations
Frequently Asked Questions
What conduit are these fittings compatible with?
AIRflex® straight compression fittings are designed specifically for use with AIRflex spiral PVC and polyurethane conduits. Compatibility with other conduit types should be verified prior to installation.
What is the difference between LKI and USK fittings?
The LKI fitting features a swivel-thread design that allows rotational movement after installation, helping reduce torsional stress. The USK fitting uses a traditional compression locking nut that rigidly secures the conduit in place without rotation.
Which fitting is better for vibration or movement?
The LKI fitting is recommended for applications involving vibration, rotation, or multi-axis movement because its swivel-thread design minimizes torsional conduit stress.
Are these fittings quick-connect like FLEXAquick® fittings?
No. AIRflex® straight fittings use compression-style installation methods and do not feature the FLEXAquick® quick-connect release mechanism.
What ingress protection rating do these fittings provide?
Both LKI and USK fittings provide IP54 protection when installed in accordance with product specifications.
Need Assistance Selecting an AIRflex® Compression Fitting?
Contact IBIS Electro-Products Corp for technical guidance on AIRflex conduit systems and compression fitting selection.