Geothermal. As noted above, all engineered PP-R pipe can typically be safely buried in soil, sand or concrete. Some PP-R pipes are used in horizontal grids for geothermal applications, thereby storing the geothermal mass horizontally instead of in deep vertical wells.

Piping for Water Conservation and Gray Water Systems

Water conservation (catchment, reclaim, re-use) systems are being specified and installed much more frequently in certain areas of the continent, as building and plumbing codes are updated to encourage more responsible water use. Most codes require that these systems be kept entirely separate from the potable water supply and that the piping be color coded and labeled to identify it as non-potable. PP-R pipe with distinctive purple coloring is suited for this non-potable application (which often involves very aggressive water) due to its resistance to corrosion, scaling and microbiological growth. The water from reclaimed, recycled and rainwater sources can be used for flushing, irrigation, cleaning and other non-potable applications.

Purple pipe designed exclusively for these applications uses the same PP-R material as used for potable and hydronic applications described above, with the addition of design modifications, coloring, marking and independent third-party certification by NSF International (14).

Photos courtesy of Aquatherm

PP-R purple pipe is used for recycled, reclaimed and rainwater applications.