How To Weld Plastic Pipes Correctly

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A couple of years ago, my colleague changed the gas boiler in the country. The work took a little time: a colleague with a master bought fittings and polypropylene pipes, left the keys to the master, and the next day everything was ready. I appreciated the work: the boiler is perfectly installed, heating was also carried out, 5 radiators were installed — and all this for 1 den. My colleague liked everything, including the price. And I thought about it: isn’t the price for a one-day job too high? Just in case, I consulted with a familiar builder. He named the price for connecting the boiler and oriented it according to the cost per point (heating radiator, for example) — the amount has converged.

A couple of months later I was invited to a master class on the installation of heating of a country house. There they give master classes for everyone, including on the construction and laying of communications. The teacher clearly explained how to properly weld plastic pipes. It seemed to me extremely useful to listen to a specialist, because in the future I wanted to try to conduct plumbing in the country myself.

Tools for welding PP pipes

So, what will you need to install a water pipe or a heating system made of polypropylene pipes? First of all, it is necessary to purchase a device for welding plastic pipes. Many people call it a soldering iron. The prices for such a device are very different. Usually, the device comes with three sets of nozzles for the most common pipes with a diameter of 20, 25, 32 mm (outer diameter). Plastic pipe can be sawed with a jigsaw, cut with a grinder, but it is not very convenient. It is better to cut the pipe, and for this there is a special pruner-scissors on sale.

They cut the pipe much faster, and the cut turns out much smoother, without any burrs. In the store, this pruner is called “scissors for plastic pipes”.

But in fact, these scissors are very similar to a reinforced garden pruner, and they cut branches perfectly.

Let’s return to the issue of welding PP pipes. Please note that all the characteristics of the polypropylene pipe are written directly on it.

If the maximum temperature on the pipe is +95 ° C, this pipe is for heating, +20 ° C is for plumbing.

Getting started

We install a nozzle on the device for the diameter of the pipes that you are going to weld. Turn on the welding machine. We wait until it heats up to +260 ° C (the green light should light up).

We take two parts that need to be welded: a pipe and a coupling with a diameter of 25 mm. According to the table in the instructions for the welding machine, we specify the warm-up time. For the 25th pipe – 7 seconds or a little more. The pipe must not be overheated in any case! Carefully put the pipe and coupling on the welding machine.

No need to twist the details! It should be immediately planted strictly perpendicular to the soldering iron. Counting down 7 seconds.

We remove the blanks and connect them without twisting when combining! During the first 4-5 seconds, you can change the position of the parts, for example, straighten the connection.

At first I thought that the teacher was wrong to explain everything to us on his fingers. In appearance, the work is simply elementary! But then he began to show what could happen if the pipes were welded incorrectly.

Welding errors

To check the welding quality, it is necessary to cut the pipes along the welded joint. If the border of the weld is visible on the cut, it means that something went wrong. And such a connection can leak sooner or later. Usually such an error occurs when parts overheat, the nozzle on the soldering iron is curved, or if you twist the workpieces during docking.

When the parts overheat, another very unpleasant defect may occur — the passage section is greatly narrowed.

If the plumber messed up during installation, unfortunately, you will not be able to control it in any way. You will wonder why the water in the pipe does not flow, the pressure is small, the battery does not heat or heats very little.

What is the conclusion from this? If you are going to carry out heating in the country with your own hands, do not be lazy, practice and make a dozen test welded joints. Cut them up, see what you get.

The second stage of the plastic pipe welding training can be the manufacture of a product needed in a country farm, for example, a stool. She is never superfluous at the dacha! Having soldered the stool, you will feel all the subtleties of the plastic welding process. And your jambs when assembling the stool will not lead to leaks of the heating system or plumbing.

Why do you need an expensive soldering iron?

Sometimes it may be necessary to weld a large diameter pipe — 40 mm, for example. There was no such nozzle in the set of my device. But I bought a set of two nozzles — 32 mm and 40 mm.

In the store, I asked the teacher a question that bothered me: “Why buy an expensive soldering iron when you can find a cheap one?” He replied: “A good soldering iron differs from a budget one only by the quality of the Teflon coating of the welding nozzles. A budget plastic can start to burn in six months, and a professional soldering iron works normally for 10 years with daily use.”

Draw your own conclusions, now I will definitely make a water pipe at the dacha myself, and from the remains to weld a bunch of useful things.


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