Socket Fusion Welding
Socket welding is generally used with pipe/fitting diameters of ½” through 4”. This is a widely used technique for joining plastic piping systems using injection moulded fittings. The operating principles are straightforward, with the welding cycle basically consisting of a heating phase and a cooling/welding phase. To obtain a proper fusion, be sure to cut and mark the pipe to the proper depth. The pipe and fitting are heated for a specified period of time, after which the pipe is inserted into the fitting to cool.
Butt Fusion Welding
This technique is generally used for pipe and fittings ranging from 6” and larger. The process involves the joining of plain-end pipe with plain-end fittings. The pipe and fittings are heated while being pressed against a “heated plate” for a specified period of time. The heat is absorbed into the pipe and fitting, allowing them to weld together, and then cooled. Welding and cooling time is determined by the pipe diameter and wall thickness.
The electrofusion process involves the use of moulded socket fittings containing an electric heating coil. The pipe ends are inserted into the sockets and clamped. An electrical current is then passed through the coil for a pre-set time. Heating of the surrounding plastic and heat transfer to the pipe wall then takes place. This process is commonly used where space is limited and/or lateral pipe movement is not possible.
This method may be used as an alternative to using reducing tees. The fusion outlets can be fused to the outside of the pipe with ease. Fusion outlets are socket fused using welding heads and heating irons.
The main features of the safety-pol system are:
■ patented aquatechnik® tools flare the pipe around the fitting to maintain precise inside
diameters of the fittings, reducing pressure drops throughout the fittings
■ the pipe is locked on the fitting by a tight collar/cap connection, but can be unlocked and used again.