Longline Systems: LLS

Longline systems based on a three-phase series-resistance heating cable LLS are used to prevent freezing or maintain temperature in pipelines of intermediate length (up to 4 km). LLS systems can be installed above ground or underground, including in explosion hazardous areas.

  • Heated section length up to 4 km
  • High heat generation up to 40 W/m
  • High efficiency, large heat transfer surface area and flexibility
  • Full set of control tools and accessories
  • Single connection to the power source to minimize the cost of the cable system
  • Easy installation
Operating principle
  1. Heating cores of copper wire
  2. Silicone rubber insulation
  3. Tinned copper wire armor
  4. Silicone rubber jacket

Longline heat tracing system is based on LLS heating cable which is composed of three parallel heating cores of copper wire insulated by silicone rubber, covered by a tinned copper wire armor and a silicone rubber jacket.

The heating cores are sized to support the desired heat generation by the required circuit length. Heating cables are connected directly to a three-phase power supply or, if required, to a step-up transformer.

The large heat transfer surface of the flat heating cable reduces operating temperature compared to similar heating cables with a cylindrical conductor design, thereby improving the efficiency, safety and service life of the heating cable.

LLS cables can be arranged in a straight line or spirally on a pipe. On pre-insulated pipelines the cables are usually routed via conduits mounted on the pipe under the thermal insulation.

The heating cable is delivered in convenient lengths for serial connection on site or as ready-made heating sections.

The system minimizes the number of power source connections and thus reduces the required investment into power supply networks.

Technical Data
Maximum operating temperature +130 °С
Maximum permissible temperature without load +180 °С
Ambient temperature range −60…+55 °С
Minimum installation temperature −60 °С
Power supply Three-phase up to 900·V depending on version for specific application
Heat generation Up to 40 W/m depending on version for specific application
Ex-marking 1Ex e IIC T3 Gb X
Heating core cross-section 1.5 mm2, 3.0 mm2, 6.0 mm2

Please note that the manufacturer can change the dimensions of the cores to provide the required heat generation (W/m) at a given circuit length.

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