Floor drain
A drain set into the floor. Plans mark it with the letters FD.
This explains what a symbol represents on a drawing. Conventions vary between firms and standards, and a drawing's own legend takes precedence.
How to read it
The Army's print-reading manual gives the floor drain the abbreviation FD, shown with the symbol. The Navy's Utilitiesman course describes a floor drain as one used to drain overflow water. The Navy's Engineering Aid course defines a floor drain as a receptacle that takes water drained from the floor into the drainage system, and says floor drains are usually located near heating equipment, near laundry equipment and near any unit subject to overflow or leakage.
Also searched as: FD.
More blueprint symbols
Sources
- Construction Print Reading in the Field, TM 5-704 / AFM 85-27, Departments of the Army and the Air Force, fig. 3-8
- Utilitiesman Basic, NAVEDTRA 14265A, Naval Education and Training Command, U.S. Navy, ch. 1, sec. 2.4.2
- Engineering Aid 3 (NAVEDTRA 14069), Nonresident training course, April 1995, Naval Education and Training Command (copy hosted by Navy Tribe), Ch. 8, plumbing terms
Last reviewed September 24, 2026 by Rory Hansen. How we research