Material

• The core material in ABS pipes and fittings is a thermoplastic resin known as acrylonitrile butadiene styrene, or ABS for short. The pipes have a foam core, and the edge of each piece of pipe needs to be glued less than 1 inch for it to maintain resistance against high pressure. PVC pipes, also known as CPVC, are made from a thermoplastic material known as chlorinated poly-vinyl chloride. The main structural difference between the two types is that ABS as a material is more flexible than PVC, and can deform under sun exposure.
  
  

ABS Uses

• ABS pipes are extensively used in DWV applications, and more than 10 billion feet of the material have been installed by constructors in residential and commercial structures. ABS is used in both ground and above-ground applications, and may also be installed outdoors, provided the pipes meet certain conditions. Based on local regulations, outdoor usage may require the pipes to contain pigments to prevent it from ultraviolet radiation or to be painted with a water-based latex paint.
  
  

PVC Uses

• PVC pipes are most suited to distribute water across a range of temperatures. At room temperatures, the pipes have a 400 psi (pounds per square inch) pressure rating, and at 180 F, the pressure rating is 100 psi. PVC pipes are resistant to most common household chemicals, and since the material does not support combustion and cannot burn without a fuel source, it is used as an alternative to traditional steel and copper-based pipes in sprinkler installations.
  
  

Markings

• Both ABS and PVC pipe types are required by regulatory bodies to contain physical markings on the body. Even if the pipes are cut in relatively small pieces, the markings must be clearly visible on the surface; some local regulations mandate that the markings appear in every 5 feet of pipe length. Along with manufacturer's name and trademark, the marks contain information about conformance to standards, size, type of resin and schedule number. Markings for pressure ratings are included in PVC pipes but is absent in ABS pipes, whereas a DWV identification is included in ABS pipes but absent in PVC pipes.
  
  

Installation

• Installing ABS pipes are simpler than installing PVC pipes, because the former is a one-step process whereas the latter involves two steps. In PVC installation, a purple primer must be applied before gluing together each joint, otherwise they will tear apart over time. Using purple primer is an involved and tedious process because the subtance is very viscous and can easily spread, making the piping look unprofessional. Another drawback of PVC installation is that joints must be held together for 5 to 10 seconds after applying glue, otherwise the joints will be undone; in ABS installation, the glue works right away and the joints don't have to be held together.