Waste piping systems are designed for sewerage systems arranged indoors. They do not require any special frost-resistant coating and are produced with standardized diameters (wide diameter pipes are not usually installed in the internal sewerage systems) from two types of materials. Channel pipes for internal use can be divided into types depending on the material they are made from:
Polypropylene pipes – can be quickly mounted due to the rubber seals inserted into the pipes joints, and the sewer structure itself can be assembled as a meccano. They can be stored at any temperatures in the open air. PVC (polyvinyl chloride) channel pipes have smooth internal surface that provides a low coefficient of friction allowing the water flow to run quickly and to avoid formation of any sediments. A special bell-shaped connective system including a box-coupling is used for such pipes laying.
To arrange the indoor sewerage system it is necessary to use additional connecting elements - fittings for polypropylene pipes (or PBH pipes). These parts are designed for bifurcations, pipes bends and transition areas between the pipes with one diameter and another. The pipe angle can be provided by a knee piece with different inclination angle, a plumping branch sleeve, a four-way union - these are various types of fittings that can be required when installing polyvinylchloride or propylene pipes for water supply.