The Committee on Hydrant Markings of the New England Water Works Association Submits Report and Its Chairman Comments Thereon

SOME question has been raised as to the amount of information that it is proper to attempt to convey by marking hydrants. Of course it is desirable to convey all the information possible, but it is not desirable to convey misinformation. What should be done is controlled by the degree of accuracy of the information conveyed. If the hydrants are marked as suggested in the report the information is not perfectly accurate because the number of nearby hydrants being used affects the results.

It has been suggested that hydrants be tested in groups instead of singly, but if that were done there is no standard of how many to use or which ones to use. One of the advantages of testing the hydrants singly is that the tests can be repeated at intervals and the effect of improvements to the system can be learned as well as reduced capacity due to the age of the pipes.

It has been suggested that the size of the main be painted on the hydrant, but if the hydrant were on a six-inch main the supply might be one fire stream or six, depending on the length of six-inch supply. That information would be no help.

Another suggestion has been made that more colors or more figures be used to represent small differences in quantity. I shall call that an unreasonable attempt at refinement and not justified.

It seems to me that the suggested report is as far as we should go at this time.

In those places where I have known of its being applied it has been well received by the Fire Departments and they consider the idea good.

Following is the report of the Committee on Hydrant Markings of the New England Water Works Association:

Report of Committee on Hydrant Markings

To the New England Water Works Association:

Your committee on the Standard Markings of Fire Hydrants submitted the following report:

This subject is of importance to all water utilities and Fire Departments.

If every hydrant in a water works is tested to learn the amount of water it will deliver at a given residual pressure and the hydrant is marked to show the result, the Fire Department will be able to work to better advantage and the Water Works officers will have valuable records.

If the system of marking is uniform, Fire Departments from other towns will be able in time of emergency to locate at the proper hydrants.

It is desirable that the capacity of all hydrants be determined at the same residual pressure and that the full capacity when supplying pumpers be known.

For this reason a residual pressure of 10 pounds has been adopted for the standard.


Markings should be determined by flow test, and should be divided into 3 classes, A, B, and C.

Class A. Hydrants which have sufficient capacity to supply 1,000 or more gallons per minute.

Class B. Hydrants which have sufficient capacity to supply not less than 500 gallons per minute.

Class C. Hydrants with insufficient capacity to supply 500 gallons per minute.

Post Hydrant Markings

Barrels of all hydrants should be chrome yellow for visibility.

Class A. Tops and nozzle caps should be green.

When the capacity of the hydrant is greater than 2,000 gallons per minute, a number should be painted on the barrel of the hydrant signifying the number of thousand gallons per minute exceeded.

Class B. Tops and nozzle caps yellow.

Class C. Tops and nozzle caps red.

The colorings conform to standard traffic signals with green the most desirable, and red the least desirable.

Flush Hydrant Colorings

All location markers for flush hydrants should carry upon their background, the colors designating the class in which that particular hydrant falls.

All flush hydrant covers should carry upon the under side, preferably within the circle, the proper color as a background upon which any necessary data could be stencilled in black.

Respectfully submitted,




(Presented before the March meeting of the New England Water Works Association at Boston.)

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