MIL-HDBK-1164
(3)
Remove old packing or O-rings.
(4)
Refinish the working parts by grinding, sanding or polishing,
and lapping. Replace all parts beyond repair.
(5)
Replace the valve parts; repack and test the valve for proper
operation.
8.4
Hydrants. Fire hydrants are mainly used for fire protection. Other uses
include flushing water mains and sewers, and filling tank trucks for street washing and
tree spraying. Hydrants may also be used as a temporary water source for construction
jobs. General information related to types of hydrants, component parts, O&M, common
operating problems, records, and hydrant safety is included in pars. 2.1.4 and 2.2.41.
8.4.1
Hydrant O&M. Maintenance procedures for specific types of hydrants are
provided in Table 26. Additional details are provided below.
8.4.1.1
Hydrant Inspection. Hydrants are inspected and tested by water utility
personnel accompanied by a fire department representative, according to command
and field engineering office directives. Hydrants can usually be maintained by
replacing all worn parts and seats through the top of the hydrant. The operator is
generally responsible for ensuring that the proper tools are used. Each year, test the
hydrant for tightness of joints and fittings in the following manner:
a)
Remove one hydrant cap and replace it with a cap fitted with a
pressure gage. Open the valve slowly until it is wide open. Record the pressure.
b)
Check for leakage at the following points:
(1)
Hydrant Top. If a leak is found, remove the cover plate and
tighten or repack the seal.
(2)
Nozzles Entering Barrel. For leaks here, caulk the
connection with lead.
(3)
Nozzle Caps. If the nozzle caps are leaking, replace any
defective gaskets.
(4)
Cracks in Barrel. For leaks from cracks in the barrel, install
a new barrel or a new hydrant.
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