Prepared by PPI’s Building & Construction Division, PPI TN-31Differences Between Crosslinked Polyethylene (PEX) and Polybutylene (PB) Piping Systems for Potable Water Plumbing Applications discusses the advantages of modern PEX tubing and fittings as compared with PB tubing and fittings, which were last sold in the U.S. during the late 1990s.
When I first entered the trades in 1972, residential tank-style water heaters shipped with the aquastat set to approximately 140° F. Dishwashers had no need to incorporate a sanitizing cycle. Around 1977, water heater manufacturers were required to lower the aquastat temperature setting to approximately 120°, and now, dishwashers needed to incorporate a sanitizing cycle where rinse water in their reservoir was raised to 140° or higher.
Xirtec CPVC is a system of dimensionally matched pipe, fittings and valves that are certified for use in noncombustible construction, high buildings and air-return plenums.
Copper alloy structures have changed drastically within the past decade to comply with low lead requirements for potable water. Common compositions added to the new alloys were bismuth, silicon, or binary alloys. The creation of these new brass and bronze structures resulted in concerns with valve performance by both engineers and contractors.
