Flexa PA12+ and PA12F+ - multilayer cable protection for railway applications

Flexa PA12+ and PA12F+ - multilayer cable protection for railway applications

Cable protection tubing plays a major role in protecting the cables of machines and industrial devices, but they show their maximum potential especially in railway transport. Among the numerous manufacturers of protective conduits, few have a full range of products dedicated to railway applications. In this respect, the FLEXA company stands out, as it is constantly developing a line of products compliant with the EN 45545 standard. New in the offer are multi-layer conduits PA12+ and PA12F+, which are characterized by impressive resistance to alternating bending in extreme working conditions. Well-thought-out functionalities of the protective conduit also significantly affect the safety and ease of use of the application.

The first huge advantage of PA12+ and PA12F+ conduits is the material from which they are made. The features that distinguish Nylon 12 (PA 12) are high resistance to temperature fluctuations, abrasion and limiting the negative impact of acids and solvents on its structure. The choice of this material allowed the manufacturer to meet a number of international standards and make the described protective tubing ideal for use in rail vehicles. However, the use of two layers allowed to significantly increase the number of alternative bending cycles, thanks to which the conduit retains its excellent operating parameters much longer and in more difficult conditions than standard solutions, e.g. at very low temperatures.

The multi-layer structure and clear color differentiation of the inner layer make it easier to locate and eliminate sensitive application points in the event of abrasion of the outer layer of the component, in addition to increasing the efficiency and durability of the conduit. Identification of the component is facilitated by color distinction: PA12+ has a red inner layer, PA12F+ has an orange inner layer. In addition, improved sliding properties of the inner layer make it easier to guide the cable and significantly reduce the risk of its abrasion.

In addition to the color of the inner layer, both variants also differ in the degree of fire protection in accordance with the EN 45545-2 standard:

  • in the case of PA12F+ it is thehighest level of protection: HL3 - the protective pipe is suitable for the most demanding applications in rail transport, among others. incl. in dynamic railway applications and devices installed in metro tunnels;
  • PA12+ has the HL2 level - still ensuring effective fire protection in many less demanding applications. The conduit is more attractively priced and at the same time does not lose its key feature, which is resistance to alternative bending. The product will therefore also be used in other industries: in solutions that automate industrial plants, in the maritime industry and in machine construction.

FLEXA PA12+ and PA12F+

The most important features and advantages of PA12+ and PA12F+ protective pipes:

  • made of reliable polymer PA 12 (Nylon 12),
  • extreme alternating bending strength in extreme external conditions (low temperatures, strong wind, snow, hail) and mechanical damage
  • wide operating temperature range from -50°C to +120°C and in short-term intervals even up to +150°C,
  • highly self-extinguishing products enriched with flame retardant – V2 classification in accordance with UL 94,
  • exceptional resistance to oils and gasoline,
  • increased resistance to acids and solvents,
  • no silicone, cadmium and halogen in the composition
  • resistance to weather conditions and UV radiation makes PA12+ and PA12F+ conduits perfect for outdoor applications,
  • meet a number of international standards:
    • VDE certificate in the DIN EN 61386-23 standard guaranteeing safety when working with electrical installations,
    • compliance with the RoHS directive and the REACH regulation,
    • PA12+ casing pipe has been approved by Lloyd's Register as a product that meets the requirements of marine applications,
  • despite being made using more modern technology, PA12+ and PA12F+ pipes remain competitively priced compared to reinforced, single-layer PA12 conduits.

The described pipes will be used in all components of rail vehicles exposed to frequent alternating bending of the conduit, where durable, safe and reliable cable routing is important. Their model effectiveness will be proven, among others, as part of:

  • couplers,
  • electrical connections between vehicles,
  • conduit routing systems through roof and floor,
  • railway trolleys.


The advantages of PA12+ and PA12F+ conduits in simplified terms, as well as fragments of the tests that the protective pipes were subjected to, are presented in the video below:

Additionally, in applications where the conduit is exposed to intense bending, it is worth considering the use of the RQMR-MOVE movable insert designed for the RQM clamping system, together with PA12+ and PA12F+ protective pipes. It significantly improves cable protection (strain relief) and is suitable for railway applications thanks to UL 94 V0 and 45545-2 certificates at the HL3 level.

The RQM system is shown in the video below (fragment about the RQMR-MOVE insert from 1 min. 47 sec.):

PA12+ and PA12F+ protective pipes have another undoubted advantage: are compatible with all FLEXAquick connectors based on the revolutionary quick connector system, which speed up and facilitate installation and subsequent maintenance, which clearly translates into installation efficiency.

The video shows how connectors with the FLEXAquick system work:

The hoses can be tightly guided through the obstruction to the exit using either a suitable quick-connector or a conduit gland:

It is also possible to use a customised conduit system when conducting them: