Winter 2014
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repair
example, the heater in a wooden Chicago
water tank malfunctioned in March and the
water inside froze solid. The tank’s structural
integrity was compromised and the tank had
to be dismantled later that month.
(3)
Changes in temperature can cause pipes to
expand and contract making them vulnerable
to breaks and leaks. Therefore, all pipes
subjected to freezing or temperature change
should be protected with insulation and heat
tracing. The pipes inside small dry risers of
elevated water tanks should also be insulated
to prevent the inlet and outlet pipes from
freezing. In January, a water pipe broke
underneath the foundation of a Minnesota
water tower and nearly 500,000 gallons of
water was drained from the tank in a mere
thirty minutes.
(4)
Pipe connections and expansion joint
connections should be monitored closely for
leaks. Leaks hidden behind insulation can be
difficult to locate, and insulation should be
inspected and replaced as needed to reveal any
defects hidden behind it and to remain effective.
The American Water Works Association
(AWWA), NFPA and Occupational Safety &
Health Association (OSHA) have devised a
system of codes and standards that contain
several recommendations on pipe inspections
and a suggested timetable for inspecting each
type of pipe.
Pumps, altitude valves, and overflow pipes
should be checked before winter to prevent
malfunctions.An overflow to grademay freeze
solid if screens are plugged or flap valves are
stuck, and vents can become clogged with ice
and snow if they are not vacuum pressured
and frost proof. Pumps or altitude valves
that fail to shut off during tank filling can
cause the tank to overflow. AWWA states, “A
properly operated tank should not overflow
during normal operation. An overflowing
tank is considered an emergency condition
and the malfunction causing the overflow
should be determined and corrected as soon
as possible.” AWWA does not recommend
the water temperature at or above 42°F
to prevent tank freezing, and the water
temperature can be monitored by installing
a low-water temperature alarm.
(2)
But, to
maintain appropriate temperature, heating
may be necessary. Insulation and standby
electric heaters can be used for systems not
already setup for steam or hot water.
All heater pipes, heating elements and
temperature alarms should be tested,
inspected and replaced as needed before the
heating season begins and monthly thereafter
or malfunctions are likely to occur. For
“Obtaining accurate
information and saving the
documentation of every
inspection and repair can enable
a deeper level of understanding
about the tank’s history”
Frozen NY Bolted Tank
Frozen EWT
