What Is a Drainage Fixture Unit Plumbing?

Drainage fixture units (DFUs) are plumbing specifications that determine the drain capacity of fixtures and service systems. They do not represent flow rates, but rather are based on fixture characteristics. One unit equals one cubic foot of water drained over a period of one minute. DFUs are used in water supply and waste water design. If you’re unsure of the term, here are some facts about them. The number of FUs in a drainage system is measured by the group value. If there is more than one fixture in a single group, the DFUs are higher than the number of fixtures in that group. The smaller pipe sizes are connected to larger ones, so a 2.5-bath plumbing system has four dfu fixtures. A dfu drain serving a single full bath group and a half-bath group is five times larger than the drain serving the kitchen sink. For example, if you have three sinks, two toilets and two bath tubs, your drain line should be at least 5 dfu. However, the larger pipes that connect to smaller ones will be used to drain them, while the smaller ones are for one-bath group only. Moreover, the size of a full bath group should be five dfu. It is also important to understand that a single full bath group has two separate drains, so you should be aware of this before purchasing a pipe for it. Click here to learn more about combi boiler derby.