Toilet Myth Busting: Water Saving Toilets Carry The LoadBy
Many plumbing professionals worry about the ability of water saving toilets to sufficiently carry waste to the sewer. While architects typically determine the sizing, pitch and venting requirements for drain lines, Professor Toilet and other toilet scientists focus exclusively on the science of effective flushing.
Coined “Drain Line Carry,” the ASME Standard requires that every toilet – regardless of water volume used in a flush – be able to drive 100 ¾-inch polypro balls down a 3-inch rigid pipe an average of 40 feet. All of American Standard’s water closets meet this standard and many, including Champion 4, Cadet 3, Colony FitRight, Evolution2 and H2Option, exceed that requirement by more than 16 feet. Here’s where we test:
Helping to transport waste through drain lines is what engineers term “supplemental flow,” or additional water generated from faucets, showers, clothes washing, etc., which is obviously more prevalent in residential than commercial applications.
In other words, drain line clogging isn’t likely to be caused by a water saving toilet. Other common causes of drain line clogging are broken or misaligned pipes, buildup of grease or grit within the drain, as well as flushing inappropriate materials.
Special note to commercial building professionals: Installations with extremely long drain lines (e.g., shopping malls or industrial sites), may require evaluation on a site-by-site basis, especially if no supplemental flows are available.