the depth of water at piping entry location. In ponds, use low water
level, if known, to ensure operation during droughts. A minimum of two
feet of water over the pipe is necessary to avoid cavitation for
A floating, non-vortexing intake installation eliminates these requirements, as noted in Dry Hydrant Standards Code 432. The USDA Natural Resources Conservation Service can assist in design and water source certification.
See Illustration C -- Slotted Intake
|Lift in excess of 15 feet should be avoided. The lift is calculated from the centerline of pump to the expected drought elevation of the water source.|
site conditions to consider:
map showing the exact site of the hydrant furnished to the local Fire
Department (911 address suggested.
A letter of approval to use the site obtained from the landowner, filed at the local Fire Department
|Illustration A shows an installation of a conventional Dry Hydrant using 45 degree elbows. Installation B shows installation with 90 degree elbows.|
D shows hydrant head approximately 2 feet above ground - and also 10 feet
from road surface. Should be more than 20 feet when more than one
pumper is to use the hydrant.
Other designs and practice standards for Dry Hydrants Code 432 may be obtained from USDA Natural Resources Conservation Services (NRCS Alabama -- August 1999)
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