421 Cherokee Drive
Trussville, Alabama 35173
(205) 655-9123
(205) 655-4149 Fax

Serving the needs of a growing community ... with Pride, Courage and Integrity.

The scope of this page is to explain the fire hydrant marking system. The City of Trussville has adopted the NFPA(National Fire Protection Association's) codes, and use them as our standard for many of our fire department procedures.

NFPA 291

Recommended Practice for
Fire Flow Testing and Marking of Hydrants

Fire flow tests are conducted on water distribution systems to determine the rate of flow available at various locations for
firefighting purposes.

A certain residual pressure in the mains is specified at which the rate of flow should be available. Additional benefit is derived from fire flow tests by the indication of possible deficiencies, such as tuberculation of piping or closed valves or both, which
could be corrected to ensure adequate fire flows as needed.

Class AA                           Class A


Class B                              Class C                         Flush Only

NFPA 291.5.1
MARKING OF HYDRANTS


CLASSIFICATION OF HYDRANTS. - Hydrants should be classified in accordance with their rated capacities [at 20 psi (1.4 bar) residual pressure or other designated value] as follows:

(1) Class AA --- Rated Capacity of 1500 gpm or Greater
(2) Class A --- Rated Capacity of 1000 - 1499 gpm
(3) Class B --- Rated Capacity of 500 - 999 gpm
(4) Class C --- Rated Capacity of less than 500 gpm

NFPA 291.5.2.1.2
PUBLIC HYDRANTS

The tops and nozzle caps should be painted with the following capacity-indicating color scheme to provide simplicity and consistency with colors used in signal work for safety, danger, and intermediate condition:

(1) Class AA --- Light Blue
(2) Class A --- Green
(3) Class B --- Orange
(4) Class C --- Red