One, must choose the quality qualified hot melt welder.
Shan temperature control should be correct. PP-R Hot Melt Welding temperature is: 253. If the temperature is below 253 Shan, the pipes and fittings are only a thin surface of the melting, once they are fused between, the strength of the weld is not guaranteed, this is what we usually call false welding phenomenon; Conversely, if the temperature is above 274 Shan, the surface molecules of pipes and fittings are destroyed by high temperature, so that pp-r form thin liquid, after connecting will make the pipe diameter smaller, more importantly, the connection part will occur brittle crack, especially in the piping system completed after the water pressure, Such problems often occur.
Shan constant temperature time is long. The length of the constant temperature is one of the important symbols of the performance of hot-melt welding equipment. Hot-melt equipment still has a heat consumption problem after heating up to set temperature, especially in the winter, the tuyere, even in the non operating gap, its heat consumption is also very large, and once the operation, its pipes and fittings are separately consumed heat energy, which requires the equipment has a strong thermal storage capacity and timely replenishment capacity.
Second, must choose the qualified and suitable welding sleeve.
The qualified welding sleeve is designed to fully consider the transverse structure and weld depth of the pipe after welding, as well as the surface viscosity and surface smoothness. At present, the domestic production of hot melt welding method of pp-R, PPC, PE and other water pipes manufacturers have hundreds of. Because the manufacturers of the production of raw materials, additives, different environmental conditions, equipment selection, so that the production of pipe and pipe size is different. Therefore, the pipe manufacturers and users must choose their own pipe diameter welding sleeve. For the operator, after the last welding should be required to clean the surface of the welding sleeve to avoid impurities in the welding part.
For the pipe with more than 40mm caliber, because of the large caliber and the ability of non personal power, it is necessary to use mechanical equipment to ensure the depth and straightness of pipe entering the pipe. We found that in many construction sites with five to six workers on a 110mm interface for welding, fee Dickens can not guarantee the pipe straightness and insertion depth, the entire pipeline winding, it is difficult to imagine in a certain temperature and pressure conditions.
The main reasons are as follows:
Shan the surface of the welding sleeve is not properly disposed, or the surface coating falls off to make the contact part of the pipe produce sand hole;
The welding surface of the pipe is not cleaned before the Shan welding.
Preparation of Shan hot-melt welding
The Shan is cleaned with a cleaning machine (or alcohol) and a brush to the surface of the weld part of the pipe;
Shan when a pre assembled part is fused, the connection is marked in the position required by the pipe and the fitting.
Shan Hot Melt and connection
Shan The tubes and fittings are inserted into the heating sleeve and the heating head, do not rotate or move too fast (to make the material melt time).
After the Shan is heated, remove the pipes and fittings from the heating element and do not rotate the heating part.
Shan the pipe and fittings are pressed along the axis immediately after heating, do not rotate. Strictly adhere to the hot-melt welding standards to maintain the time and cooling time.