The art of cunning: how to make a thread on polypropylene pipes, if there is no coupling

Threaded connections have been weakening in recent years. This is due to the advent of plastic pipes, which are connected by soldering. However, a certain amount of piping is assembled using old techniques. To make a quality connection of metal pipes, you can do threading with a crescent.

Threading with a crescent cutter

Materials for making

For threading and testing, you will need

thread, polypropylene, pipe
  • pieces of polypropylene pipe; ;
  • die;
  • metal socket with male and female threads
  • plastic coupling without threads;
  • plug on the pipe;
  • a pair of pipe tongs;
  • linen packing;
  • sealant;
  • A high-pressure test stand.

Threading of propylene pipe by cold mechanical method with an ordinary die

Put on a die and use a pipe wrench to turn the pipe, running it in the die to the right distance. Do it carefully not to weaken the pipe by making dents in it.

As a result we get this thread: it looks unpresentable, but we’ll put off the final conclusions until the test.

We cut a thread with a welder for plastic pipe and a metal socket

We heat the other end of the polypropylene pipe in a welder until it softens.

Screwing it into the ready metal coupling.

Allow the joint to cool. It is easy to unscrew the pipe from the socket.

The result is this thread: in the beginning it is almost not threaded, but at the end it looks pretty good.

We cut an inside thread on plastic socket by means of a soldering iron and a metal socket

Heat the plastic socket on the welding machine.

Let the plastic cool down and unscrew the metal coupling. The threads are almost the same as the factory coupling.

Do the same thing with the second side of the sleeve.

Threading in 3 steps

What counts as the most important thing when threading pipes? The thread pitch should match the pitch of the fittings for which it is actually threaded. This is what guarantees the tightness and durability of the connection, as well as its ability to withstand high pressure. In order to do this, you need to find the right clevis. there are a couple of other things to consider when tapping a pipe. Let’s describe it step by step.

Stage 1. You need to clean the pipe of all dirt and rust (if it is an old pipe). After that you need to chamfer the pipe. you can use a file for this. This makes it easier to screw on the clip. Secure the pipe before you get to the threading tool.

Step 2. To fix the tool in the holder, to center its cutting part on the workpiece, lubricate the pipe with machine oil or solidol. it will facilitate the turning of the tool, exclude the appearance of galling on the thread and reduces the wear of cutting edges.

Stage 3. Start turning the handle of the tongs, the first bits in the tongs will start to thread, and the next ones will finish it for more accuracy and precision. The thread pitch is equal to the number of full rotary movements. You need to lubricate the pipe while working.

That’s it! Minimum effort, minimum tool purchase costs, minimum time. that’s how you thread with a club. See for yourself by doing a sample or two on several pieces of pipe. Next, you can thread smoothly and accurately on pipes that are installed in the water system of your apartment or private home.

In our online store you can find hand held clips of various diameters. We only carry genuine products so you can be sure of getting a clean, even thread. find the right tool for the job right now, while most sizes are in stock!

Threading with a tap

To thread inside the pipe you usually use a tapping tool. It is shaped like a rod with cutting edges. It must be inserted into a special screwdriver.

  • The fence part. Is a cone that threads directly into the pipe. The teeth of the taps are positioned around the entire circumference.
  • Calibration part. This element is an extension of the intake part and has the form of a cylinder on which the teeth.
  • Tail part. Has a square head and is designed to hold the tap in the hole.

To ensure that the tool does not overheat during operation, different media are used for cooling:

If the cooler is not enough, the profile may turn out uneven or with roughness.

Specialists advise using complete taps in the work. Includes tool for roughing and finishing work. By eliminating at least one of the taps, you will not save much time, but the quality of the final result can be low.

Connection methods

Welding is the best option for:

  • universal pipes PN 20. they withstand water temperature of 80 °. Their walls are much thicker than the previous two.
  • pipes PN 25, reinforced (aluminum foil) polypropylene, for hot water and central heating. These pipes can withstand a water temperature of 95 °.

The popularity of polypropylene pipes in the simplicity of all their connections, available to people even without special training. Therefore, the question of how to connect polypropylene pipes is most often solved independently.

Connections can be mechanical, separable with a thread or inseparable. by welding.

Welding machine, metal socket and pipe

In this case the threading is facilitated and runs standard. We heat the end of the pipe according to the instructions to the machine and start screwing it into a metal socket with an internal thread. In this case it is necessary to commensurate with the pressing force and speed of rotation.

Screwed the pipe to the required depth, let it cool down a little and reduced in size. After that it can be easily unscrewed from the metal coupling. Inspection shows that the thread does not start at the end of the pipe, but at some distance, but it looks quite fit and reliable.

Basic reasons for failure

No one is immune to the possibility that the result of your work will be defective.

Simple Trick for Cutting Pipe Threads in Plastic (TIS334)

What could be the reason for it?

  • The mismatch in the cross-section of holes or rods of grooves to be cut.
  • Using a poor quality tool (blunted or not centered correctly).
  • Not using any lubricants.
  • Lack of skill.

Using tools for professional work

In a professional job, of course you would use a good clupe, such as Rems or Regis. When you use an electric tool for tapping you save a lot of time, effort and space.

Like threading a piece of pipe.

Thanks to the included holder, threading is easy to do without an assistant:

But in some places, the electric tool does not reach the pipe because the pipe is too close to the wall. Sometimes even a manual ratchet can’t fit, so you have to work with a wrench.

thread, polypropylene, pipe

By “compactness” I meant that when working with a ratchet or wrench, you need to have space for maneuvering. Т.е. the swing because of the big lever. With the electric tool does not need a swing.

That’s the way it is. If there are any questions, please ask them in Комментарии и мнения владельцев or in a specially designed for this heading “SanSoviet”

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