If you have ever wondered about how water moves around in the buildings you design (other than leaky walls and roofs), you probably know that I'm talking about pipes. If you don't, then here's an architect friendly discourse:
Short for Polyvinyl Chloride. PVC pipes are cheap, durable and good enough for most plumbing applications. Remember- no hot water in PVC pipes. PVC pipes are typically joined using solvent cements resulting in a good leak resistant joint. Solvent cements are not essentially lung friendly and if you care about the good folks who put together your building, make sure there is plenty of ventilation during installation.
Chlorinated Polyvinyl Chloride. We won't talk about the chemistry but somehow that 'c' allows the pipes to withstand higher pressure and temperature so go ahead and use it for hot water connections. Like PVC pipes, cPVC pipes can be used for potable water but they have a reputation of supporting bacteria growth on the inside and can impart a plasticky taste to water.
High Density Polyethylene. HDPE is stronger than PVC and the pipes can be manufactured in greater lengths and diameters. Coiled lengths of unto 1000 feet are available for certain sizes making the pipe ideal for long runs with minimal joints. In addition pipe lengths can be heat fused eliminating toxic cements and resulting in stronger leak proof joints. HDPE is a lot more versatile material and if you still choose not to use HDPE pipes in your project, you will still end up with a milk jug or a bottle or a chair made of HDPE. Oh and Tyvek is made of HDPE.
: stands for 'Soil, Waste & Rain'. It's just a PVC or uPVC (rigid PVC) piping system designed for drainage.
What about GI or copper?
GI or Galvanized iron is still used in plumbing but have been overshadowed by PVC pipes. GI pipes are much more sturdier than PVC. Unlike PVC/cPVC pipes, they don't burn and emit toxic fumes in case of fire. GI pipes are prone to corrosion (inspire of galvanization) and there is a concern about using the pipes for potable water use as they contain lead.
Copper is a proven material in plumbing and recommended for long term durability if you can prevent the pipes from getting stolen during construction and can find a plumber who knows copper plumbing (good luck). Copper is 'biostatic'- it inhibits bacterial growth. They do have downsides other than cost and labor intensive installation. Heat welded/ soldered copper pipe joints are leak proof but may fail if water gets too hot (180 F/ 82C). They could be noisy at high water velocities and are not suitable for acidic water.