Moulding the Chemical Resistant Liner

A film of material is applied to the mould and, thereafter, the first plies of special glass reinforcements are laid up and retain a very high percentage of corrosion resistant resin. This operation enables a fully impermeable wall to be obtained with a high resistance to chemicals.

Winding the Reinforcement

The structural part of the pipe is made by the filament winding of continuous glass yarns (roving) impregnated with resin. The pitch of the winding spiral and, thereby, the angle formed between the yarns and the axis of the pipe are determined during the design work and depends on the stresses to be withstood. At the same time as filament winding is taking place.
The internal or box thread of epoxy pipes is made during the initial phase of filament winding process, through the automatic winding of glass and resin on the ends of the pipe.

Curing and facing

To prevent the resin from dropping, the curing operation is carried out while the pipe is rotating in its own axis.  Curing of epoxy pipes is made in special oven at temperature ranging up to 150°C.
Then facing of extremities is made so that to allow the extraction of the pipe from the mandrel.

Extraction

The pipe bar is extracted from the mandrel; this operation takes place in a dedicated working station controlled by a system which allows to automatically carrying out the different working phases.
Grinding the Areas of the Joints
After extraction, epoxy pipe is placed on the rectifying machine for rectification of the ends and for machining of the grooves for O-ring and lock joints, where required.

Testing

Manufacturing of the pipes is subjected to constant checking. The checks are carried out on the raw materials, at each production phase and, lastly, on the finished product. The mechanical strength of finished products is tested periodically on lengths of pipe chosen at random from standard products. The test consists in reproducing the conditions which the pipes will have to undergo during working and also, in a dimensional check. The inspected pipe, if accepted, is indelibly marked with indications relevant to manufacturer lot, manufacturing date, diameter, pressure class and then is sent to the factory stockyard waiting for shipping.