A Roadmap of AST Codes and Standards
AST codes and standards can make or break an AST purchase. Wayne B. Geyer reports on the major code requirements that impact AST purchasing decisions, and tells PE&T readers how to determine out which ones could apply to them.
What you don’t know can hurt you
Imagine spending thousands of dollars on an aboveground storage (AST) system, and finding out too late that you can’t install it because of certain local fire regulations. Could this nightmare come true? The answer is “yes.” The old saying “What you don’t know won’t hurt you” is completely untrue about many things, including AST codes and standards.
In order to make informed decisions, tank buyers, engineers, architects and local fire marshals need to familiarize themselves with the evolving technology of ASTs, as well as the various national, state and local fire codes that govern AST installation. Such an understanding will dictate whether a tank can, or should, be installed underground or aboveground.
In the Nov./Dec. issue, I discussed AST technology (“AST Fuel Dispensing Systems Today”). In this article I will discuss code organizations and their requirements for the installation of AST systems as the subject affects our industry, and thus our wallets.
An explosive subject
Fire prevention authorities contend that storing large quantities of flammable and combustible liquids in ASTs carries more risk than storing these liquids in underground tanks, since ASTs are more accessible to the public than USTs. This concern has been the impetus for many codes for ASTs and AST fuel dispensing systems.
Hard experience, however, does not entirely bear out this concern, particularly in terms of shop fabricated (less than 50,000 gallon) ASTs. It has been nearly 30 years since the last recorded US fatalities occurred from an AST fuel dispensing system fire caused by a shop-fabricated AST. On July 31, 1968, an explosion of a 10,000 gallon aboveground gasoline tank caused three deaths in Kennedale, Texas. The AST was a factory built skid tank, common at self-service stations of the time, with a baffle in the tank, dividing it into two compartments: 7,000 gallons at one end and 3,000 gallons at the opposite end. The tank had one two-inch vent, which should have been at least four inches to handle any discharge overflow, and no emergency vent. (Over pressurization will not occur if it has a properly installed and maintained emergency vent.)
Large AST process pressure vessels pose more of a threat than factory made ASTs, because of their larger size and pressurized containment. However, there is always a greater potential for risk with any ASTs because, in most cases (except with vaulted tanks), the tanks are out in the open. Therefore, fire codes seek to reduce the possibility of hazardous or catastrophic incidents. System fleet fueling applications, for example, place perhaps hundreds of people near an AST.
Major players
In the March/April 1996 issue of PE&T, columnist Marshall Klein looked at the major code options for ASTs. He notes:
“There are four national codes enforced in different parts of the United States—three of them model fire codes (see Table): the Standard Fire Prevention Code (SFC); the BOCA National Fire Prevention Code (BOCA); and the Uniform Fire Code (UFC). The fourth code is the National Fire Protection Association’s Automotive & Marine Service Station Code (NFPA 30A).”
Taken out of context, Marshall’s statement might seem to indicate that by looking at a map of the United States, you will be able to determine which state is regulated by which code. However, this is hardly the case. For instance, in Texas, where some big cities have adopted UFC (the Uniform Fire Code); some small cities have adopted SBCCI (the Southern Building Code Congress International); and rural areas often use NFPA (the National Fire Protection Association). See Marshall Klein’s table above for AST options for service stations.
Here is a brief description of the four national code organizations that provide AST codes:
• The National Fire Protection Association (NFPA) oversees two of the more widely known codes for ASTs. The NFPA 30 Code is the Flammable and Combustible Liquids Code. The NFPA 30A code is the Automotive and Marine Service Station Code, for the dispensing of motor fuels for vehicles at service stations. Both codes refer to a number of construction and installation standards, such as those developed by Underwriters Laboratories (UL), the Steel Tank Institute (STI), the Petroleum Equipment Institute (PEI) and the American Petroleum Institute (API). NFPA 30 and 30A are predominantly used in the midwest and eastern US, yet are often referenced overseas as well.
NFPA has a different structure than other model code organizations, which permit only code officials and enforcers to vote upon changes in codes. Instead, NFPA uses consensus committees to develop codes, and no more than one-third of any single interest group is allowed to vote. These interest groups—which include manufacturers, fire enforcers, insurance representatives, engineers and end users—provide a balance to the code process.
• The Uniform Fire Code, published by the International Fire Code Institute (IFCI), is predominant in the western half of the US. Until recently, the UFC prohibited aboveground tanks at any type of service station, whether a fleet or a retail operation. In 1991, the IFCI changed this rule by adopting Appendix II-F, which provides requirements for any type of aboveground fueling facility and in 1994, Appendix A-II-F-1, the testing requirements for protected tanks. The rule required all tanks to be secondarily contained and to have two hour fire ratings. Qualification requirements of this tank were added to another appendix and eventually formed the basis of a portion of UL 2085, Insulated Aboveground Tanks for Flammable and Combustible Liquids.
The UFC held a hearing in December 1996. Its committee will recommend to the IFCI membership that:
1. Appendix II-F be incorporated into the main body of the UFC code.
2. UL 2085 be added as an approved standard.
3. Emergency venting be required for all confined/enclosed spaces.
4. An exception be allowed for diking of ASTs with “listed” integral secondary containment.
• ASTs are also regulated by the National Fire Prevention Code for the Building Officials and Code Administrators (BOCA). Chapter 23 applies to the storage, handling and processing of all hazardous liquids, while Chapter 32 contains flammable and combustible liquid requirements. BOCA oversees many of the building codes in the US.
• Yet another code-making body is the Southern Building Code Congress International (SBCCI). In 1994, the SBCCI adopted NFPA 30A nearly verbatim for its fuel dispensing requirements at non-retail facilities throughout the Standard Fire Prevention Code. Like BOCA, SBCCI oversees many US building codes.
Normally, national model fire codes (UFC, BOCA, SFPC) are revised to a minor extent every year, and these revisions are published in annual supplements. The local Authority Having Jurisdiction (AHJ) must then decide whether to incorporate these revisions into their existing codes. The model fire code agencies will typically publish the entire code every three years, as does NFPA.
Service Station Layout: Minimum Property Size
UL 2085
This figure illustrates the minimum property size for 3/6000 fire resistant or vaulted tanks with dispensers mounted atop tanks.
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UL 2085 |  |
Local jurisdictions
Do not assume that a particular jurisdiction has adopted all the codes of a particular code body, UFC or NFPA 30 for instance, just because the jurisdiction says it has adopted them. In fact, the local AHJ can adopt all or parts of a particular code as law if it so chooses. For instance, until recently, the City of Chicago would not allow aboveground gasoline dispensing tank systems, even though the State of Illinois had adopted NFPA 30A as its standard. In this case, the local AHJ (Chicago) adopted more stringent codes than those adopted by the state, based on the City’s concerns for densely populated areas.
Codes from the four national organizations are recommendations, and become law when the local AHJ formally adopts them. However, the word “recommendations” can be somewhat misleading because: (1) they are generally enforced as law on a local level; and (2) you will be held legally responsible for the consequences of not using code “recommendations,” both on a short and long term basis. This includes the adoption of industry-recognized recommended practices (RPs).
Other than the codes, recommended installation practices in the petroleum equipment industry for ASTs come principally from Petroleum Equipment Institute’s (PEI) RP200. These practices are widely considered prudent to follow, whatever the codes may be. More often than not, RP200 more than satisfies the requirements of the various codes for ASTs. Yet, RP200 can’t be assumed to cover all local AHJ codes.
The bottom line is that in all cases, AST installations must meet the approval of the local AHJ. In other words, the fire service can insist that motor vehicle fuel dispensing systems be installed underground, regardless of what the code allows, based on concerns for public safety.
In the case of the Uniform Fire Code, not only must the local jurisdiction adopt the UFC but the AHJ must also adopt the additional appendices.
Fire-rated ASTs
Over the last several years, fire-rated, or insulated, ASTs have received a great deal of positive attention from fire regulators, particularly for fuel storage and dispensing applications. This recognition has been translated into an easing, in some instances, of the ordinances governing AST installations, particularly with insulated tanks.
Different codes use different terminology to describe insulated tanks. The National Fire Protection Association refers to an insulated AST as “fire-resistant,” while the Uniform Fire Code terms it “protected.” All ASTs that are termed insulated, fire-resistant or protected must pass a two-hour fire rating. Still another term commonly used for fire-rated tanks is “thermally protected.” (For more on fire-rated ASTs, refer to my article in the last issue of PE&T.)
One code for all? Recently, the IFCI, BOCA and SBCCI have formed a new organization—the International Code Council (ICC)—which aims to meld the model fire codes into a single code, International Fire Code (IFC) in North America by the year 2000. The NFPA is participating as a partner to ICC, rather than an ICC member. This undertaking is described in the Nov./Dec. issue of Tank Talk, published by Steel Tank Institute (“Codes Galore”):
“Committees composed of representatives from NFPA, BOCA, SBCCI, IFCI and various fire chief and fire marshal organizations will develop the new code. The committee will appoint at least 50 percent of their members from the fire code enforcement community (i.e., the authority having jurisdiction). In forming a common code, these committees will be used to recommend language changes and resolve any inherent conflicts between the various codes.”
The question of who gets to vote on codes has served as a major barrier to NFPA’s membership in ICC—and therefore, a barrier to the final structure of the International Fire Code and its committees. At the time of this publication, sources say the NFPA and ICC have resolved all remaining issues and only final signatures are required. An ambitious plan is in the works so that the first draft of the IFC can be released by Summer of 1997.
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UL 142 |  |
UL 142 tanks
There is an important rule of thumb for fuel storage in non-insulated assemblies: the further a tank is from important buildings and property lines, the less of a hazard it presents to the public. Here, ASTs installed at private locations (i.e., commercial, industrial, government and manufacturing facilities) require less stringent separation, since they present less exposure and, hence, less of a hazard to the public. They also tend to be better secured.
As mentioned earlier, separation distances are specified in each code. The tank must be installed a minimum distance from property lines, fuel dispensers, buildings and public ways. Again, these separation distances will vary by code and by the type of AST (UL-142, if allowed, and insulated/protected).
Separation distances also are specified between tanks and dispensers and delivery trucks as a fire prevention matter. If a fire should occur at the tank or at the dispenser truck as a result of overfill, malfunctioning equipment or human error, the separation distance will serve to contain the fire in one area without immediately exposing the other element to fire and subsequent pollution.
Go directly to City Hall
If you have the impression that AST codes can be confusing and require careful study, then I’ve achieved one of my goals. Of course, I hope I’ve cleared up some confusion about the “whats and whys” of national model fire codes. But above all, brand this thought into your consciousness: the very first step in any proposed AST installation project is to contact the local AHJ.
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