General
Conduit type	metal conduit
Material	Zinc-plated steel
Temperature range	-50 °C
Approval	VDE-tested in accordance with EN IEC 61386-23
Conformity	REACH
Application range	Interior area
Packaging type	Coiled
Features	Extremely flexible

The metal protection conduit SPR-AS, type AD21, from Flexa is a helically wound protection tube made of galvanized steel, designed for use in installations subject to high mechanical stress. It is supplied in a pack with a length of 10 meters and features an S-profile that enables high flexibility and tensile strength. The protection conduit is intended for indoor use; for outdoor applications, the stainless steel variant SPR-VA is recommended. It is particularly suitable for applications in machine building, plant engineering, vehicle construction, rail vehicles, shipbuilding, automation, as well as in electrical installations and EX areas in accordance with EN 1127-1.

Applications

The protection conduit is designed for installations where cables and lines must be protected against mechanical influences such as transverse pressure, tensile load, or bending stress. It is frequently used in industrial environments where high demands are placed on mechanical stability and durability. Use in EX areas (explosion-hazard areas) is permitted according to EN 1127-1, although the specific approval must be verified depending on the application and environmental conditions. Use outdoors is not recommended, as the galvanized steel construction is more sensitive to weather influences such as moisture or salt exposure.

Functions and Equipment in Detail

The protection conduit is characterized by its high flexibility, enabling easy installation even in tight or curved runs. The tensile strength ensures that it maintains its shape and function even under mechanical stress. The transverse pressure resistance protects the installed lines from damage caused by external pressure forces. The S-profile provides an optimal combination of flexibility and stability. The use of galvanized steel offers good corrosion protection in indoor environments, with the surface being resistant to moisture and minor environmental stresses.

Technology Explained Simply

The protection conduit consists of a corrugated, helically wound steel tube, which gains high bending and tensile strength through the S-profile. The galvanization protects the steel material from oxidation and corrosion, particularly in dry indoor environments. The temperature range of -50 °C to +250 °C makes it suitable for applications in extreme environments, such as industrial processes with high or low temperatures. Certification according to EN IEC 61386-23 ensures electrical safety and mechanical reliability.

Compatibility and Accessories

The protection conduit can be combined with various cable glands and clamps to achieve a secure and tight connection. Compatible accessories include metal cable glands such as US-M AD21-M20 or LI-M AD21-M20, made of nickel-plated brass, suitable for secure attachment to devices or enclosures. Right-angle cable glands such as USW-M AD21-M25 or hose clamps such as SKM AD21-22 are also available. For special applications, such as high temperatures, PTFE sealing rings are available for use with US cable glands. The end cap EEM AD21 enables a clean termination at the end of the conduit.

Installation and Mounting

Installation is carried out by laying the helically wound protection conduit along the desired cable route. The flexibility of the S-profile allows adaptation to curves and angles. Fixing is done using appropriate cable glands or clamps at the ends or intermediate points. During installation, care must be taken to avoid excessive bending or crushing of the conduit to maintain its mechanical integrity. The use of swivel cable glands (e.g., LI-M) facilitates installation, especially in tight spaces.

Operational Advantages

The protection conduit provides reliable mechanical protection for cables and lines in demanding environments. The high flexibility and tensile strength ensure a long service life and minimize the risk of breaks or deformations. The galvanization protects the material from corrosion in indoor environments, increasing operational safety. Certifications according to EN IEC 61386-23 and compliance with REACH and RoHS ensure adherence to European safety and environmental standards. Use in EX areas extends the application range in sensitive industrial facilities.