Unsoftened polyvinyl chloride (PVC-U) pipes are used in household gravity sewage systems. Due to well developed joining material they are often used for manufacturing household connections and joining them with different type of sewage systems.
Two basic types are:
Compact PVC wall-lined UKC pipes - Full walled pipes
Full walled pipes are manufactured in accordance with SIST EN 1401-1 standard. Compact pipe wall means same material is used for entire pipe thickness.
Full walled PVC pipes are renowned for a number od excellent characteristics:
Good corrosion resistance
Smooth inner surface insures good hydraulic properties and lessens the possibility of sediment build-up
Water-tightness of the pipeline
Long lifespan and low maintenance costs
Light and consequently easy for transport and installation
A large number of different joining and fitting elements
Coex or co-extruded PVC pipes are mad of three layers. Inner and outer layer are made of thin and compact PVC material, while the middle layer is usually regenerated PVC, regenerated foam or foamed PVC. Coex pipe is cheaper alternative to compact PVC pipe.
Coex pipe are manufactured in accordance with SIST EN 13476-1 standard.
Coex pipes have properties similar to compact PVC pipes, but the foamed middle layer makes them:
Less stressful for the environment, due to use of regenerated materials