MAINTAINING HALON INVENTORIES
Courtesy of Steve Johnson, Nevada Cogeneration
Many LM user's have packages and other plant areas equipped with Halon fire protection systems. Over the years, Halon has proven to be an effective means of controlling fire in contained spaces, while presenting the least harm to personnel and equipment. As a result of the Montreal Protocol, however, all manufacturing of Halon 1301 by the countries that signed the agreement ceased on December 31, 1993. An additional federal excise tax of $43.50 per pound was added to the normal sales taxes on the "virgin" Halon still available, driving prices above $75 per pound.
At present, there is no overriding obligation for user's to remove existing Halon systems. In fact, wholesale disposal of existing systems would be counter-productive to the environmental goals of the Montreal Protocol. The first, and usually most cost effective consideration of a current Halon user is to maintain the existing fire protection system through procurement of "recycled" Halon to replace the current inventory following a discharge. The recycled Halon carries no added taxes and is available from a number of sources. Some of these sources include:
1) Surplus Halon may be available from sister plants, partnerships or a parent company following modification of a fire protection system to another fire protection agent. In fact, most larger corporations have an in-house exchange system that tracks the supply and demand of surplus Halon for the company's facilities.
2) Reprocessed or surplus Halon is available from fire protection companies such as American Fire Company, Ansul, FireMaster and Statewide Automatic Fire Electronics. Other companies dealing with recycled Halon include the Wood Group and a non-profit organization called the Halon Recycling Corporation. Typically, this Halon is collected from retro-fits of systems changed to another agent. The Halon is then processed to 98% of the original manufacturing specifications, the balance being inert nitrogen gas which does not interfere with the fire suppression.
3) Recycled or surplus Halon is also available on the open market from individual brokers such as Snyder Fire and Allstate. Usually, this source of recycled Halon is available following decommissioning or modification at another facility, such as a hospital, hotel, ship, or etc. Pricing for this Halon often fluctuates, though a typical range is from $22 to $42 per pound. Remember that these are businesses and to make a profit they must pay well below market value to sellers and charge at or above market price to buyers. Deliveries are usually based on a first-come-first-served basis and are normally availble only on short notice.
A replacement policy should be determined before procuring Halon for spare inventory. For example, a priority use for Halon is in areas that contain electrical and control equipment which are occupied on a continual basis, such as Control Rooms. A lower priority would be for areas that are only occasionally occupied, such as an electrical, switch gear or I/O room. The lowest priority, though still an important consideration, are areas where personnel do not enter while operating but which contain critical mechanical and electrical equipment, such as a gas turbine or generator. Eventually, this type of fire protection policy will provide a basis for phasing out Halon in lower priority areas and extending the life of Halon systems in the higher priority areas.
To determine how much Halon is needed for the spare inventory, first survey the bottles in service and total the pounds of Halon. If possible, the replacement Halon should be obtained in the same sized bottles so that the bottles can be easily replaced and refilled with minimum impact on plant operations. For example, the S&S LM2500 package contains two 250 pound Pyr-A-Lon bottles, so a pair of these bottles should be inventoried. As a suggestion, flexhose connections should be used with all bottle installations to minimize losses during change-out.
Some fire protection companies may be able to obtain 2,000 pounds of recycled or reprocessed Halon in a one ton cylinder or "pig." Note that the pig may have to be purchased separately for about $1,500. Having a single container is attractive as it requires only one weight check and sample, however, it necessitates the use of a large forklift to unload and move. Storing such a large and heavy object in limited warehouse spaces may also be a problem. On the other hand, a large number of small bottles could result in higher transfer losses and still create storage problems.
Recovery or recapture of the Halon when transferring to an empty bottle varies from 85% to 99.9%. Use of dry ice on the bottles in an insulated box will improve transfer from 85% to 88-90%. One system used for recapturing 98% of the Halon costs around $5,000. Additional nitrogen separation and filtration systems can be used to return the Halon 1301 to its original specifications for an added $17,500. This specialty equipment may not be economically feasible unless costs are shared with a contractor or a number of other users. Considering the cost of Halon, it is recommended that the transfer system employed by either the user or contractor be evaluated and the potential transfer losses factored into spare inventory purchases.
As a final suggestion, receiving of the spare Halon should be closely monitored. The gross weight of the bottles should be either certified by the supplier or weighed on-site at delivery. This may require renting a portable scale which can handle the largest bottle. Subtracting the tare weight stamped on the bottle will determine the net weight of the Halon. The bottles should be set on pallets to simplify moving and storage. Ensure that each bottle has a working pressure gage so that leaks or transfers can be monitored. Number the bottles. List the gross weight and end use locations, such as "Control Room," with indelible ink below the tare weight stamp. A person responsible for warehousing should maintain a record of the inventory.
If a verification of the Halon quality is desired, a sample from one or more bottles can be taken and sent off to a third party lab for analysis by infrared spectroscopy. The infrared spectrum should be identical to the bromotrifluromethane spectrum provided by the original Halon manufacturer, such as Aldrich Chemical Co. Purity of the Halon can be deduced from an analysis of the percent nitrogen in the sample.
So, happy Halon hunting! Remember to lock-out those fire protection systems during maintenance. Since inventorying Halon will only extend the life of existing systems, consideration of Halon alternatives (or revision of the Montreal Protocol) will be necessary in the future.
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