The Socket welding process, which is known as poly-fusion, snap-in welding and embossing fusion too,  consists in using a kind of  female/male welding matrices, which gets heated at the same time, in the inside and the outside part of the fitting , the inside and the outside part and the pipe, so when they are hot they could be joined using the pressure.

In other words, the socket welding it is performed by snapping in the inside pipe the fitting, and both parts, achieve the temperature enough to fuse the material.

So, the outside pipe gets hot, when the fitting its placed inside, note that the two components must be made of the same material composition.

A really important point is, to have in mind which are the steps to follow in order to perform a successful union between pipes and fittings.

The most common plastic materials used are:

  • Polyethylene (PE)
  • Polypropylene (PP)
  • Vinylidene Polyfluoride (PVDF)

The process that we must follow for this welding are:  

  1. Clean the pipe ends and bevel them in order to be able to entry in the fitting easily.
  2. Mark the tube, with the insertion dept, in order to know how far the pipe has to entry in the saddle.
  3. Check that the inside fitting it is clean too.
  4. Place the heating mirror in the saddle corresponding to the measure that we are going to weld and put to heat.
  5. Check with an external thermometer and with a contact prove, that the saddles male/female, effectively achieves the temperature requested for a properly plastic fusion operation.
  1. Once we have achieved to the needed temperature, we must introduce at the same time, the pipe inside the female saddle and the fitting in the male saddle, proceeding with such a pressure as they arrive at the end at the same moment.
  2. Once they arrive to the end, we must leave them to get hot without pressure, the seconds within, that the welding table indicates.
  3. Once this time has elapsed, when the heating process has been done, remove the pipe and the fitting from the molds with caution, and together till the fitting until contact the cold ring.
  1. Apply a continuous pressure till the necessary cooling time gets accomplish and once achieved, we must leave the welding to settle for ten minutes.

Socket welding Equipment.

There are manual and hydraulic equipment with the them you could proceed to perform Socket welding, depending of the diameter to weld will me more convenient one or other machines.


the saddles they should not be cleaned using elements that can degrade their surface, and it is advisable to use alcohol wipes to proceed with their cleaning.

It is also very important, to be taken this equipment to an authorized maintenance center, for its regular revision.

the Spider 125, a perfect Machine for this type of welds.

The Spider 125 is a welding accessory for pipes socket welding and PP-R fittings up to 125mm.

It is a compact and light devise which dispose or a hard transfer screw with a parallel joining system that join the pipes and the fittings in a properly alignment way without any type of diversion.

The Spider 125 features permitting that a solely technician could make the proper alignment, heat, fusion and cold the pipe. This is because the pressure it is constant throughout all the process and doesn’t present any regression.