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TEAM
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TANK MAINTENANCE -vs- TANK MANAGEMENT The municipal
tank owner has been the target of questionable practices for many years: stories
abound about the town that had an emergency repair and paint job after a
“maintenance contractor” made a free inspection and found that the tank was
in despicable condition which, if not repaired immediately, would be in danger
of imminent catastrophic failure. Proper
tank maintenance is essential.
A properly maintained tank can last 100 years or longer.
The key is defining “proper maintenance”. Tank maintenance
contracts are not new: they have been around for as long as there have been tank
painting contractors. The basic premise of the maintenance contract is that for
a fixed yearly fee, the contractor will keep the tank in good repair. This is
good! The problem: whose definition of “good repair” is to be used? In this
article we will examine a sample of the content of a maintenance contract, and
expose areas of possible problems. Tank
Maintenance For over 18
years a medium sized city had several elevated water tanks under a maintenance
contract. During this time, maintenance, painting and repairs were routinely
performed. In fact, the city paid extra at one point to have all the rods and
struts on one tank replaced. Before continuing with a maintenance contract, this
city decided to have an assessment inspection performed by an engineering firm.
This assessment revealed that: • The
tanks were in extreme disrepair; • The
ladders on one tank were unsafe; • The
roof was so corroded that much of it, including the roof vent and hatch,
required replacement; • The
“maintenance work” consisted of applying paint over rusted and improperly
prepared surfaces; • One
column was so deteriorated that a 30 ft section had to be replaced; • Examination
of the rods that had been replaced revealed that they were undersized for
required wind design. • Examination
of the maintenance contract revealed that the contractor had performed the
obligations as outlined in the contract document. This is not an
isolated case... We have
encountered other similar situations where a city or town had a “maintenance
contract” on their tank, but little or no real upkeep had ever been performed.
The problem invariably is the lack of specific performance criteria. Following are
the requirements of an actual five year maintenance contract for an
elevated water tank: INTERIOR
SURFACES 1. To annually
inspect the interior of the water tank. 2. To annually
remove all sediment and debris from the interior of the water tank. EXTERIOR
SURFACES 1. To annually
inspect the exterior of the water tank and tower. 2. To annually
spot coat wherever necessary the paint on the exterior of tank and tower. 3. To apply every five (5) years a new coating of good quality aluminum paint.” It doesn’t
require a Philadelphia lawyer to realize that there are no standards of
performance for the materials or workmanship to reference the work that is to be
done. The contractor will essentially do whatever he feels will be required to
fulfill this contract: the owner is entirely at the mercy of the contractor’s
integrity. Management
Approach In the past 10
years there have been tremendous changes in the tank and paint industry. Some of
the old standby protective coatings are no longer in use due to their effect on
the environment. Lead based paint on existing structures has become cause for
serious environmental consideration. New exotic
coatings have been introduced which are superior to all earlier materials if
properly applied. The cost of a paint job today can, in many cases, exceed the
cost of the original structure 20 years ago. Improperly specified or applied,
these new coatings will fall far short of their expected or promised
performance. A systematic
program involving engineers specializing in the inspection, specification and
design of steel storage vessels is recommended to help establish a
cost-effective management/ maintenance program to assure that comprehensive
performance standards are established before maintenance work is undertaken. The management
program includes the following elements: PRELIMINARY TANK
ASSESSMENT: This first
element of the management program involves a complete inspection of the tank for
the purpose of determining the condition of the tank and making a detailed
engineering report on the findings. This evaluation is made on the structure,
foundations, coatings and appurtenances. A complete assessment report is
prepared and various options are presented for a desired cost-effective tank
maintenance cycle. SPECIFICATIONS: After the owner
selects a desired maintenance program, detailed specifications are prepared to
cover the work required, using the latest in tank and coating technology. INSPECTION DURING PROGRESS: No matter how
“tight” the specification, or how good the material used, the real key to a
long lasting paint or repair job is quality of workmanship. An inspection
program utilizing trained and experienced field inspection personnel is needed
to assure quality contractor performance. MAINTENANCE/MANAGEMENT PROGRAM: After the tank
is placed in service the next scheduled inspection is the warranty inspection,
which includes the participation of the contractor. Any deficiencies in the work
performed under the contract are repaired at no cost to the owner. This
inspection also gives the owner a rate of corrosion factor which will be used to
schedule future inspections and possible maintenance repairs. Who Is Qualified? Water storage
tanks are engineered structures subject to high stress factors. Structural
failure due to corrosion and neglect can cause loss of life and property. The minimum
requirement for water tank inspections should be the AWWA Standard D101-53.
Section A-1.2 of that standard states that: “...this inspection service shall be performed by organizations or individuals who are properly qualified to do such work. Those properly qualified are: 1. An engineering organization whose principals are registered professional engineers, specializing in inspection service and having at least five years’ experience in the inspection of steel structures, or 2. Independent engineers, licensed in the state in which the structure is located, whose practice has included substantial or major attention to steel construction, or 3. Inspection or safety agencies of the state ....” The conclusion
is that it is in the best interests of the tank owner to have a “tank
management” program which clearly establishes standards of performance. Under
the direction of an engineer or engineering firm, criteria for evaluating the
maintenance program can be established. With this frame of reference, nobody
ever needs to be surprised or disappointed with the results.. What you don’t know can not only hurt you, but it can cost a lot of money. |
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