What is PVC and its use in compressed air pipes
It is the most versatile plastic material known, one of the most used in the world: ranging from the “vinyl” of old records to gutters, from drinking water pipes to electric cables, from windows to packaging film, from clothes to wigs, from industrial warehouses to tensile structures and lorries’ covers. It is PVC, code of polymer of vinyl chloride (or polyvinylchloride), chemical formula (CH2CHCl) n.
Pure, it is a rigid material; it owes its application versatility to the possibility of being mixed even in high proportions to inorganic compounds and to plasticizing products, which make it flexible and moldable: it can be molded by hot molding in the desired shapes, extruded, calendered or reduced to liquid for coating of fabrics, surfaces, reservoirs, valves, faucets, tanks and artificial textile fibers. It is considered stable and safe in technological applications at room temperature, but extremely dangerous if burned or heated at high temperatures, due to the presence of chlorine in the molecule, which can be released as hydrochloric acid.
A particularly important use of PVC concerns the manufacture of pipes that are used for the transport of compressed air and liquids for industrial use, fundamental in the agricultural and food sector, but also used in construction, automotive, boating, in the building and throughout what concerns the maintenance.
Flexibility and versatility are the basis of the extraordinary use of PVC pipes, in addition to their smooth surface and resistance to operating temperatures ranging from – 5 ° C to + 60 ° C, and in the plasticized version with polyester and fiber reinforcement polyester with an intermediate glue layer: this resistance is essential when cooling liquids, chemical solutions and liquid food, as well as compressed air, must be transported.
The pressure resistance capacity of a PVC pipe has an inverse relation to the diameter dimension, which can vary from 4 to 50 mm for those that are intended for compressed air. In PVC pipes with polyester fiber reinforcement and an intermediate glue layer, however, the pressure remains constant regardless of the diameter, but it is the temperature that has influence.
The compressed air tubes – there are different types of different diameter and length, as well as thickness of the rubber – can be flexible while maintaining the characteristics of reliability, durability and tolerance to high pressure. To manufacture them it is necessary to follow a particular process, which evaluates the rubber that supplies the covering and the fibers placed inside; in particular, the rubber needs a high pressure extrusion process and the same pipe must then be submerged in cold water, so as to harden in a short time.
Flexible PVC pipes have a considerable field of application, especially in industry and in mechanical workshops: for example, compressors for painting car bodywork, in general all types of compressors that need safe and long-lasting interventions.