welding technology Due to modern progress and technologies, we are able to use only the best materials and equipment in almost every field of our activity, including in the field of water supply. We all remember how a fairly long time water supply was carried out with the help of metal pipes. Then they were replaced by plastic and metal-plastic pipes, which for quite a short time replaced a significant part of the metal and cast iron counterparts from the market. However, the use of metal plastic products is not always convenient, so another option appeared on the market - HDPE pipes, which quickly became in demand in the water supply sector. 
HDPE pipe is a product of low pressure polyethylene, the bright advantages of which are:
- light weight;
- no interactions with water, so the smack of metal has remained in the past;
- is not corroded, which, in cases of underground installation, eliminates the need to insulate the pipe;
- longevity, the pipe is not damaged when freezing water;
- is easy to assemble the pipeline;
- low cost.
Welding technology consists in heating the edges of the pipe to a temperature at which the polyethylene becomes viscous, after which the heated edges are connected under pressure and held until the moment of cooling. 
Butt welding is carried out in several stages:
- Mounting and fixing pipes in the centralizer of the welding machine;
- Trimming by installing a face-piece on the centralizer between the pipe ends;
- Visual check of coincidence of ends, as well as checking the gap between them.
- Heating and melting of the ends.
- Connection of the ends under pressure and their further cooling.
For butt welding, it is especially important to control the heating temperature of the ends, the heating time and the pressure during connection.
Butt welding rules
Butt welding of HDPE pipes should only be carried out on flat and hard surfaces( boards, asphalt, etc.).It is necessary to ensure alignment of welded pipes( the difference in axes should not exceed 10% of the wall thickness).Non-weldable ends must be closed with plugs to avoid drafts and ensure a constant temperature of joining. 
Before starting work, it is necessary to wipe the ends with a lint-free cloth, as well as the clamps of the centralizer. Pipes must be positioned in such a way that their marking is in the same line. It is also necessary to remove dust and various microparticles from the heater by means of a test joint. For pipes with a diameter exceeding 180 mm, two test joints must be made. 
It is essential to wipe the grinding discs before grinding. After the final alignment check, you can proceed directly to the very butt welding process.
Average price for welding services for HDPE pipes
The price of welding services for pipes directly at the client's site usually depends on their diameter, type of welding, number of joints 
