Heating of pipes with heating cable: how is the process
During the construction of country houses, all measures for the insulation of communications should be provided in advance (burial in the ground below the freezing point, insulation of mineral wool, polystyrene foam, polyethylene foam), but sometimes all this is not. You may encounter a shallow trench, pipes running through an unheated room, and in such cases you can be saved by a heating cable for pipelines.
Below we look at what it is, how it is mounted, and also show you the video in this article.

Pipeline insulation
Heating cable

- A self-regulating heating cable for heating pipes is produced in the form of a tape heater, where the semiconductor polymer matrix is heated by two parallel conductors. It is noteworthy that when installing such a cable, the instruction allows you to cut it for connection in any place without fear that a cold zone will arise there. In addition, such a tape design is able to regulate the amount of heat generated by each individual section, therefore, such a cable cannot burn out in principle.
- Due to double insulation with a modified polyolefin, the device acquires mechanical protection (abrasion, impact), protection against active chemicals, water resistance and high dielectric properties.. It should be borne in mind that the price of such a resistive device is much higher than that of the PNSV, but there is practically no need for constant monitoring, since the adjustment takes place on its own.
What to consider when calculating the power

In order to choose the right resistive device, you basically need to take into account three main factors, this is 1) the power of third-party thermal insulation; 2) the material from which the pipe is made; 3) diameter of the pipeline.
Note. If you have installed a heating cable for the water supply inside the pipe, this does not mean that it no longer needs insulation. If you make additional insulation with mineral wool, polystyrene foam or polyethylene foam, it will significantly reduce heat loss, therefore, the cost of electricity will also be less.
Pipeline Diameter | |||||||
Indicators in mm | 15 | 20 | 25 | 32 | 40 | 50 | 65 |
Figures in inches | 1/2 | 3/4 | 1.0 | 1 1/4 | 1 1/2 | 2.0 | 2 1/2 |
Minimum thickness of surface insulation | |||||||
Indicators in mm | 20 | 20 | thirty | thirty | 40 | 50 | 65 |
Installation
Note. If it is a heating cable for sewage inside the pipe, then it can be purchased with any jacket, but for the water supply system, fluoropolymer insulation should have an approval for food suitability.

There are two main ways by which self-regulating heating cable for pipes is laid - indoor and outdoor installation. But for the latter method there are some options, one of which is indicated in the upper figure, so it can be tied along the pipe in the singular in a straight line, it can also be laid on both sides, and in addition, it is mounted with a wavy line or spiral.
But such options are mainly used only when sewage or water supply is already involved and there are problems with freezing, and in addition, such heating tape is used for winter heating of roofs (icing protection).

Before you buy such a device, you need to make sure that it is sold together with the kit intended for its cutting, which includes a coupling and the gland that protects the cable from the ingress of water inside, under the insulation. In addition, the installation of the heating cable inside the pipe begins with the first installation of the coupling on it, and then the gland that fits tightly to the shell.
It is desirable to make this before you trim the ends - this way you will facilitate the process - it is much more convenient and faster.
After you put your clutch and gland on with your own hands, you can start cutting and for this we will need to retreat from the edge of 100-120 mm. First, we cut the insulation along the perimeter, but we only cut it in order not to damage the screen - after the cut, bend the cable in this place several times and the cut will be complete.
After that, cut the insulation along and remove it (with the edge you can separate it with a knife - it is more convenient).

After you remove the insulation, you will have a shielding braid in front of you, which you need to weave and twist into a flagellum, as is done in the photo above - later you connect it to grounding. Now you need to release the heating matrix and to do this, retreat from the edge of the upper cut 15-20 mm and very carefully, so as not to damage the matrix itself, incise the shell around the perimeter, however, the process is exactly the same as with the upper layer.

Now you have reached the matrix itself and you need to clean the wires for connection by removing the shell from them with a knife, but this is somewhat more difficult compared to the two upper insulating layers that you got rid of. To implement your plan, turn the ribbon edge and very carefully remove the plastic, just like sharpening a pencil - you see a fragment of the process in the top photo.
Make such a sweep from two sides and gently pull the wires, spreading them around, so that you can cut off the already unnecessary shell - you can, of course, cut the matrix along the middle, but taking into account its rigidity, it will be rather difficult for you.

Now, we put a special two-channel nozzle from the kit on the bare wires, but first fill the sealant in the holes to ensure water-tightness (after installation, add the sealant to the holes again). On each core (screen including) put on plastic tubes from the same kit, and on the ends of cores there are metal tubes that you clamp with pliers or a terminal block.
Now the cable is ready for connection to a shield or a special box, as in the top photo.
Note. The reverse end of the cable must be sealed. To do this, remove 20-25 mm of the top insulation, leave 5-7 mm of the screen there and shorten one of the matrix wires by 5 mm - no short circuit will occur.
From above you put on the heat shrinkage from the kit and heat it with a match.
Now you need to push the self-regulating heating cable inside the pipe through the fitting tee, connect the terminals and ground to the power source and the heating process will begin.
Conclusion
The entire installation of the heating cable inside the pipe does not take much time - its cutting requires much more attention and labor costs. Exactly the same procedure for connecting the tape heater and for installing it on the roof (find out here how the cable is laid in pipes of various types).