Cut Winter-Related Property Losses With Proper Planning
- Published on Tuesday, October 30, 2007
- Written by Factory Mutual Engineering and Research
“Areas that don’t usually experience severe temperature drops often are unprepared for freeze-ups and snow loads, so when they do occur, losses are large and costly,” says Croteau. “Many facilities located in these regions have little or no insulation or heating equipment, with some processes or equipment located outside. These companies also may not have planned for the business interruption that results from a winter-related loss, making the experience even more devastating.”
Recent cold winters in the southern United States prove Croteau’s point: cold weather cost Florida’s orange growers millions of dollars, but although it was not highly publicized, such industries as pulp/paper and petrochemicals also reported millions of dollars of loss damage.
For example, a pulp and paperboard mill located in a southern state shut down for a long holiday weekend and suffered a $700,000 loss when various piping systems and associated valves ruptured as a result of freezing temperatures.
Disaster recovery professionals know recovering from inclement weather is considerably easier if a proper winter weather protection plan is in place before the problem occurs. To help you develop safeguards for your company, FME&R recommends that your plan include protection strategies for all assets in your organization that could be damaged, including plant buildings (idle facilities, too), production machinery, mechanical equipment (including HVAC and refrigeration systems) and fire protection equipment.
Heavy snowfall and freezing temperatures are the two most devastating winter elements, causing roof collapses and equipment freeze-ups. Below are recommendations on how to analyze your organization’s roofs and equipment for potential damage and how you can protect them against these common problems.
Guarding Against Snow-Related Roof Collapses
FME&R loss statistics show that approximately 75 percent of snow collapses occur with buildings that have multilevel roofs, since the snow blows off the upper roof and collects on the lower roof, creating a sizable snow load. Wind may also sweep the snow across the lower roof and up against the wall of the higher building. However, heavy snowfall, especially when it is mixed with ice or hail, can be fatal for any roof not strong enough to support the extra load.
Curved roofs and canopies are also subject to collapse, and, since most severe storms are accompanied by northerly winds, buildings with higher sections to the north of lower sections are more vulnerable.
Design and age are factors that determine roof collapse potential. Most snow load collapses involve boards-on-joist roofs or steel-frame roofs of modern construction. Older, plank-on-timber and boards-on-joist roofs are also subject to snow loading. These older roofs, however, often are able to withstand the extra weight because most were built when the cost of building materials allowed roofs to be over-designed.
The risk doesn’t end when the snow stops falling. After a snowstorm, rising temperatures may create “ponds” of melted snow, which pose a significant roof collapse risk. Even worse, if the temperature drops again, it could cause this water to freeze. The resulting ice dams that form on roof edges or near drains could hinder proper drainage. Drainage also may be blocked if ice is allowed to form in the drain areas.
If you determine that roof collapse loss potential exists at your facility, you can help prevent snow load collapse by following the three guidelines below.
1. Reinforce existing roofs where the roof design cannot withstand the anticipated snow load. Loss prevention consultants can help you determine the extent of reinforcement measures that should be taken.
2. Have trained snow removal teams and appropriate snow removal equipment at sites where the loss expectancy is not high or where reinforcement is not practical.
3. Design new roofs with sufficient drainage. For existing buildings and locations where this design approach is not practical, clear snow and ice from the drains, and make paths through the snow and ice on the roof to allow water to run to drains or roof eaves. Inspect drains and drainage pats on a regular basis, especially after a winter storm.
Freeze-ups Can Lead To Costly Business Interruption
Even without precipitation, freezing temperatures can incapacitate a facility by causing mechanical and electrical breakdowns. Most frequently damaged by cold weather are sprinkler systems, process piping, compressors, instrumentation, valves and fittings, heating and air conditioning equipment, steam piping and boilers.
Consider the petrochemical manufacturing facility in the southern United States that experienced below-normal temperatures (11-20 degrees) recently. The cold caused condensation to freeze in air lines leading to process instrumentation and controls. As a result, feedwater demineralization was disrupted, and untreated water was fed into boilers.
The untreated water carried over and formed deposits in the superheater, which subsequently overheated and ruptured, disrupting the entire process operation. This chain reaction, and other problems in the facility caused by the cold snap, resulted in equipment and business losses of nearly $9 million.
Automatic sprinkler freeze-ups should be your chief concern during cold spells. Give top priority to thawing water in sprinkler piping, because frozen water will limit fire-fighting efforts and lead to greater damage than might have occurred under normal conditions.
Sprinkler and domestic water piping often is located in ceiling structures or walls closest to the exterior of a facility. Thus, water in those pipes is susceptible to freezing if the building temperature is low enough.
Water frozen in domestic piping also is dangerous because it usually is vital as feedwater for boilers and other equipment. Lack of cooling water to equipment can also cause it to overheat and eventually break down.
Consider using portable heaters and heat-tracing equipment to help keep water in pipes from freezing – particularly in exposed areas where protection is minimal due to poor insulation.
Three principles to follow when safeguarding equipment are: Remove water and moisture, add antifreeze, or provide heat. Here’s how these principles would apply to some of your equipment.
- Process Equipment (boilers, process/steam piping): Idle equipment should be completely drained, flushed with antifreeze solution, and have all compressed air blown out.
- Compressors: Provide adequate heat, locate in a heated enclosure, or provide antifreeze solution. Drain equipment not otherwise protected if freeze-up is imminent.
- Instrumentation: Drain condensed moisture frequently, provide heat tracing, and minimize the length of lines exposed to ambient temperatures.
- Valves and Fittings: Check pressure vessel vents, relief valves and safety valves before and during cold weather to assure that moving parts are functional and that openings are not obstructed by frozen condensate or foreign material. Make sure heat trace systems have adequate capacity and are in good working order.
- Heating: Maintain fuel supply and storage systems in good condition. Make sure an adequate alternate supply of fuel is available in the cold weather months. Preheating equipment for heavier fuel oils should be properly maintained to assure proper viscosity of the oil for firing.
- Air conditioning: Remove water from oil coolers and water jackets. Drain condensers of chilling units. For more effective protection, circulate an antifreeze solution through all water passages before draining.
If a facility will be unattended during the winter, a central station supervised alarm system should be provided to monitor power supply, building temperatures, low-water fuel trips on boilers, water temperatures on exposed water storage tanks and selected process controls. Set the alarm system to activate before temperatures fall below 40 degrees.
Heating and insulating systems of buildings and equipment prone to damage from freezing temperatures should be designed to keep the temperature at a minimum of 40 degrees. And, provide enough building heat in areas that are susceptible to freezing, including stairwells and out-of-the-way spaces.
If a property is idle and/or has experienced past freeze-ups, drain equipment carrying moisture that is susceptible to condensation and freezing before the winter begins. Schedule maintenance shutdowns before the onset of winter for buildings and equipment that have experienced freeze-ups in the past.
Putting A Winter-weather Protection Plan Into Action
To protect against a winter-related crisis, develop a prevention and maintenance program outlining an inspection schedule and repair procedures for all systems subject to freeze damage. Appoint a designated representative from management or operations to monitor weather conditions and implement cold weather procedures, and establish guidelines for a weather watch with procedures for alerting management and maintenance personnel.
Implement an emergency response plan to minimize downtime and production losses.
“Too many companies develop disaster or emergency response plans that just sit on the shelf collecting dust,” says Croteau. “Then when a disaster strikes, they’re not ready for it.
“Effective emergency response requires a thorough employee training program including simulated drills and other tests of the response plan.”
Croteau advises disaster management professionals to develop an Emergency Organization (EO) with personnel trained to respond to winter-weather emergencies.
“Choose EO members from employees who are likely to be available during a crisis,” Croteau says. Alternate EO members also should be named.
“When a disaster strikes, most employees will want to be with their families and homes,” he says. “If possible, you should choose those employees who live in areas less likely to be affected by a disaster that can damage a facility.”
Proper Training Is Essential
Once an EO is established and responsibilities assigned, establish a training program.
Croteau also suggests that an emergency handbook be distributed to all employees, and that regular emergency drills be conducted.
In summary, Croteau advises disaster recovery professionals not be lulled into a false sense of security. Even though several winters may pass without a major freeze, or if your facility is located in an area not normally prone to freezing weather, develop and implement an emergency action plan now. It is up to you to make sure you and your business will not be left “out in the cold.”
Factory Mutual Engineering and Research, located in Norwood, Mass., is a leading authority on property conservation counseling.
This article adapted from Vol. 5 #1..