Modelo urbano difuso en Europa, Eurosprawl

Purpose

This guideline provides information about safe practices for the storage and handling of flammable and combustible liquid fuels.

Content

General Overview SO.33-2

Guideline SO.33-2

I. Fire Characteristics of Fuels SO.33-2

II. Fuels: Storing, Handling and Dispensing, Loading and Unloading SO.33-4

Resources SO.33-5

General Overview

When storing and handling liquid fuels, such as gasoline, diesel, and jet fuel, SBUs should follow practices and codes detailed in this guideline. They are based on the practices and codes of the American Petroleum Institute and U. S. National Fire Protection Association.

Guideline

I. Fire Characteristics of Fuels

Requirements for the safe storage and handling of fuels are based on their fire characteristics, particularly the flash and boiling points, as defined by NFPA-30 (Figure SO.33-1).

A. Class I Flammable Liquids

Codes and standards restrict Class I flammable liquids most stringently because they have the propensity to vaporize at ambient conditions and to form flammable vapor mixtures in air.

B. Class II and III Liquids

As Class II and III liquids do not ordinarily vaporize at ambient conditions, they present a lower fire risk until they are heated which increases their volatility. Treat Class II and Class III liquids — stored or handled within 11°C (20°F) of their flash point —as flammable liquids. This includes considering:

Fig. SO.33-1 NFPA 30 Liquid Classifications & Definitions

Reprinted with permission from NFPA 30; Flammable and Combustible Liquids Code, Copyright  1990, National Fire Protection Association, Quincy, MA 02269. This reprinted material is not the complete and official position of the National Fire Protection Association, on the referenced subject which is represented only by the ...

NFPA-30

Classification Physical Properties Typical Uses

Class IA Flash point below 22.8°C (73°F), boiling

point below 37.8°C (100°F) Fuel additives (ether) Class IB Flash point below 22.8°C (73°F), boiling

point at or above 37.8°C (100°F) Gasoline and fuel additives (ethanol & methanol) Class IC Flash point at or above 22.8°C (73°F), and

below 37.8°C (100°F)

Class II Flash point at or above 37.8°C (100°F),

and below 60°C (140°F) Diesel, kerosene, jet fuel (Jet-A

& JP5), and fuel additives (Techroline)

Class IIIA Flash point at or above 60°C (140°F), and

below 93°C (200°F) Not commonly used as fuel in exploration and production operations

1. Ventilation (to keep vapor/air mixtures below the lower flammable limit) 2. Exposure to ignition sources

3. Drainage, diking, and impounding 4. Electrical area classification

C. Affect of Contamination on Classifications

1. In General

Contamination can change the classification of a fuel. Examples of this change include:

a. Placing a Class II liquid into a tank that last contained a Class I liquid b. Exposing a Class II liquid to the vapors of a Class I liquid through an

interconnecting vapor line 2. Contamination Limit

For guidance, be aware that, in the U.S., the Occupational Safety and Health Administration (OSHA) sets a contamination limit of one percent.

If a flammable or combustible liquid with a lower classification (more volatile) contaminates a reservoir of a liquid with a higher classification (e.g., gasoline into a diesel tank), in a concentration of one percent (by volume) or more, the entire reservoir should be considered to be composed of the lower classification.

3. Alterations to the Standard

In certain installations, the provisions of the industry standards that form the basis for this guideline may be modified. Among the special features in a facility or operation that may warrant such modifications are the following:

a. Topographic conditions b. Barricades and walls c. Adequacy of building exits d. Nature of occupancies

e. Proximity to buildings and adjacent exposures

f. Structural characteristics and construction of buildings (wood or metal frame) g. Characteristics of the liquids to be stored and handled

h. Nature of the operations at the facility

i. Degree of pre-fire planning and fire protection available at the facility j. Adequacy of local emergency responders to cope with flammable or

combustible liquid fuel fires

II. Fuels: Storing, Handling and Dispensing, Loading and Unloading

Figures SO.33-2, SO.33-3, and SO.33-4 provide references to U.S. industry standards for fuels.

Specific editions of NFPA and API codes are referenced in parentheses beside paragraph numbers because paragraphs may change from one edition to the next.

Fig. SO.33-2 Storing Fuels

Topic

Guideline

(Industry Standard) Notes

Types of Approved Storage NFPA-395; 1-2.1 (1988) Location of Storage Tanks

(with respect to property lines)

NFPA-30; 2-3.1.1 (1990) See Table 2-1

Tank Shell-to-Shell Spacing NFPA-30; 2-3.2.1 (1990) See Table 2-7 Control of Spillage from

Storage Tanks

NFPA-30; 2-3.3.2 (1990) Remote Impounding

Venting Storage Tanks NFPA-30; 2-3.3.3 (1990) NFPA-30; 2-3.4 (1990) NFPA-30; 2-3.5 (1990)

Tank Diking Tank Venting Emergency Venting Underground Storage Tanks NFPA-30; 2-4 (1990)

NFPA-30A (1990)

Underground Tanks Storage, Handling, and Dispensing

Containers and Portable Tanks NFPA-30; Chapter 4 (1990) NFPA-395; 1-3 & 1-4 (1988)

See Table 4-2.3

Tank Marking NFPA-395 (1988)

Tank Lightning Protection API-RP-2003; 3.5 (1991)

Fig. SO.33-3 Loading and Unloading Fuels

Topic

Guideline

(Industry Standard) Notes

Static Electricity Control NFPA-30; 5-4.4.1.2 (1990) API-RP-2003; 2.3 (1991) Stray Electrical Currents NFPA-30; 5-4.4.1.7 (1990)

API-RP-2003; Section 4 (1991) Tank Truck/Railcar Loading NFPA-30; 5-4.4.1 (1990)

API-RP-2003; 2.4 & 2.5 (1991) Marine Wharf Loading NFPA-30; 5-4.4.2 (1990)

API-RP-2003; 4.3.3 (1991)

Resources

Automotive and Marine Service Station Code. NFPA-30A. Quincy, MA: National Fire Protection Association, 1990.

Flammable and Combustible Liquids Code. NFPA-30. Quincy, MA: National Fire Protection Association, 1990.

National Electrical Code. NFPA-70. Quincy, MA: National Fire Protectional Association, 1993.

Protection Against Ignitions Arising out of Static, Lightning, And Stray Currents. API Recommended Practice 2003. American Petroleum Assoc., 1991.

Storage of Flammable and Combustible Liquids on Farms and Isolated Construction Projects. NFPA -395. Quincy, MA: National Fire Protection Association, 1988.

Fig. SO.33-4 Handling and Dispensing Fuels

Topic

Guideline

(Industry Standard) Notes

Electrical Area Classification NFPA-30; 5-3.5 & 5-4.1.3 (1990) NFPA-70 (1993)

Closed Containers NFPA-30; 5-4.1.1 (1990) Keep flammable liquids in closed containers or in properly vented flammable liquid cabinets.

Leakage and Spills NFPA-30; 5-4.1.2 (1990) Clean up spills promptly.

Transfer from Pressurized Containers (using air or inert gas)

NFPA-30; 5-4.1.4 (1990) • Use of air is prohibited.

• Use of inert gas is permitted, but restricted.

Pressure Relief Valves on Pumps

NFPA-30; 5-4.1.5 (1990) Use with positive displacement pumps.

Low Melting-point Materials NFPA-30; 3-3.4 (1990) Use of low melting-point materials is discouraged;

steel is preferred.

Dispensing NFPA-30A; Chps 4 & 9 (1990) NFPA-30; 5-4.3 (1990)

Motor fuel dispensing Incidental uses

Guideline SO.34