- Published on Tuesday, 30 October 2007 05:56
Corrosion can be a major factor in a loss situation and if not controlled, it can result in a substantial increase in the dollar amount of the loss.
Corrosion can be controlled if certain actions are taken immediately after the loss and specialist companies are called in for the cleanup.
INDUSTRIAL CORROSION CONTROL
Exposure to fires, floods and chemicals can cause costly and sophisticated equipment to corrode. The resulting affect can make the equipment malfunction. Restoration through corrosion control is, in most cases, faster and more cost efficient than replacement. The waiting time for new equipment also causes unnecessary downtime when corrosion control can have the company back in production in a relatively short time.
Corrosion control involves:
- the cause, extent and type of corrosion
- base metals involved
- function, configuration and complexity of corroded item
- risk involved for continued corrosive progress
- finishes involved
- accessibility for rework, repair and/or replacement
- adjacent materials which can influence chemical selection
- working environment
- manufacturer’s protective system
- cost effectiveness
Experience has shown that each job is unique. Analysis is needed to develop the right chemicals, equipment and procedures for each job. Chemists must custom formulate the chemicals for each situation. On-the-job chemical testing assures that cleaning will not damage equipment finishes.
The three major factors to be considered in developing a solution are:
An alteration in any of these, such as a change in the humidity level, can cause an immediate change in the nature of the problem and the need for a change in treatment chemicals. If the unforeseen happens, corrosion specialists must reformulate the chemicals and procedures to satisfy the changed conditions. Chemists should work with the owners chemists or metallurgists to satisfy all quality control requirements set by the owner, equipment manufacturer or government regulation. Cleaning crews work around the clock if necessary to minimize downtime.
Although each situation is unique, there is a general plan that can be adopted to slow further corrosive action by disrupting the mode of corrosion. Removing or eliminating one or more of the elements of corrosion - moisture, oxygen or corrosive media - makes a temporary reduction in corrosion action. This is done by moving the equipment from a corrosive environment or removing the corrosion-causing elements from the equipment. Water can be removed by draining, vacuuming, forced air drying, heat or solvent displacement. If some lag time is expected before thorough cleaning and treating can begin, a suitable corrosion inhibitor can be used to restrict oxygen exposure. This preliminary action can reduce further detrimental effects until the more time-consuming cleaning and treating process is accomplished. Next, a detailed plan, precisely oriented for a particular set of conditions, must be initiated. Specialized cleaning solutions are utilized. If structural problems could occur with contamination to the steel building housing the equipment, all steel members must be decontaminated and a rust-inhibiting finish applied to affected metal parts.
Following the mechanical and chemical cleaning step, equipment should be closely inspected for pitting, erosion, scratches and other damage to the base metal that can interfere with its functioning or lead to future deterioration.
HIGH-TECH CORROSION CONTROL
Smoke, water and the heat, humidity and corrosive chemicals resulting from a fire can damage all metal surfaces, especially electrical connections, electronic contact points and finetooled precision parts. Electronic data processing equipment, electronic office equipment, elevator controllers, electrical motors, and similar items are highly susceptible to this type of damage.
Most such damage results from airborne contaminants that go undetected and untreated, causing corrosion. Often it cannot be seen in the initial stages, and if corrosion is not arrested, damage can become irreparable.
A three phase approach should be considered to control corrosion and restore damaged equipment to a pre-catastrophe condition.
EMERGENCY TREATMENT - Because corrosion normally starts immediately, emergency treatment should be performed as quickly as possible to preserve the equipment. A suitable corrosion inhibiting chemical should be applied to each potentially affected surface. This emergency treatment can be accomplished very quickly and inexpensively, creating a state of preservation until the decision is made to proceed with the more time-consuming processes of restoration and recertification.
RESTORATION - The unit is disassembled and the housing and chassis are cleaned in detail. Different cleaning solutions may be needed for each electronic surface. Some detachable parts are cleaned in ultrasound tanks. Other parts are cleaned by hand, using small cotton swabs, air brushes and other specialized tools. After restoration, a protective coating is applied to prevent further damage. This greaseless, non-conductive coating usually lasts one to two years. Following the application of the protective coating, the units are reassembled.
RECERTIFICATION - The specialist cleaning contractors should work with the manufacturer’s service representative to protect the customer’s warranty and take the necessary action to recertify the equipment.
Remember - corrosion begins immediately after a disaster, and its control depends on how soon these steps are taken.
Written by Melvyn Musson, M&M Protection Consultants, Marsh & McLennan. Information in this article was provided by BMS Catastrophe, Inc., Fort Worth, Texas.
This article adapted from Vol. 2 No. 1, p. 7.