As pointed out earlier, standpipes are, in effect,
ground level storage tanks. Inspection and main-
tenance procedures for standpipes are the same as
those for ground level steel storage tanks.
If the spider rods under the roof have corroded,
remove them, as they are needed only during
Paint the roof, selecting the proper paint for the
UNDERGROUND STORAGE.When steel
storage tanks are constructed belowground or are
surrounded by an earth embankment, the semiannual
inspection and repair include only the interior of the
tank, the roof, and the accessories. The inspection and
maintenance procedures are the same as given for
ground storage steel tanks.
inspection and maintenance procedures set forth above
for ground storage steel tanks, the following specific
procedures apply to elevated storage steel tanks.
Semiannually, tower structures should be checked
for rust and corrosion, loose, missing, bowed, bent, or
broken members; loose sway bracing; misalignment of
tower legs; and evidence of unstableness. Items that
must be covered are as follows:
1. Inspect the back surface of the lattice bars and
anchor bolts, the inside of boxed channel
columns, and pockets where batten-plate
connections and column bases form pockets for
collecting trash and water. Clean and paintthese
enclosures, and fill with concrete as necessary to
2. Check the bases and the baseplates for evidence
that water has collected at that point; if water is
found, drill a 1 1/2-inch hole through the
channel-boxed section to allow complete
drainage. Then grout the baseplate with a
mixture of sand and asphalt to prevent water
from running under the plates. Taper the grout
from the top edge of the plate to the pier.
3. Check the sway bracing and tighten the
turnbuckles if necessary. Examine under clevis
pins and rod loops where corrosion may be
greatest. Drill holes in the bal cony floor to
eliminate stand ing water.
Besides general roof inspection and repair, as
described for ground storage steel tanks, obstruction
and navigation lights should be inspected and
relamped if necessary. Additional items that should be
covered are as follows:
1. Check the operation of all other lights; check
hoods, shields, and receptacle fittings; look for
missing or damaged parts. Repair or replace
parts as necessary.
2. Check lightning rods, terminals, cables, and
In cold climates, potable water storage tanks (with
small riser pipes) and elevated storage tanks (for fire
protection only) usually have heating equipment to
prevent freezing in severe low temperatures. Checks
that must be conducted are as follows:
1. Annually, 2 months before the freezing season,
inspect the riser for deterioration of the frost
covering. Seal any openings to reduce heat loss.
Also, check the heating system to ensure proper
operation during the next cold season.
2. Annually, 1 month before the freezing season,
operate the heating system for 8 hours to check
all elements under operation.
CATHODIC PROTECTION EQUIPMENT.Only
impressed current cathodic protection systems are used
for protecting steel water storage tanks against corrosion.
This system of protection may be applied to all types of
steel water tanks-ground level standpipe, underground,
and elevated. Refer to the material presented earlier in this
chapter for a discussion of inspection and maintenance
procedures for impressed current systems. Also, other
applicable procedures are as follows:
Annually, note and record the current flow during
the operation. If the current does not flow, check the
fuses, electrodes, which contact the tank, ground
wire connection to the tank, and the immersion of
electrodes. If the equipment is operating at voltages
or amperages above those listed on the nameplate,
the rectifier may be damaged.
Make certain that the connections to the
rectifier are not reversed. Reversed connec-
tions will result in tank damage.
Annually, check the operating record to
determine if the electrodes are immersed at all
times, or almost all the time. If the electrodes are
not immersed, there will be no damage to the