American Petroleum Institute

Using the  Color-Symbol System to Mark Equipment and Vehicles for Product Identification at Gasoline Dispensing Facilities and Distribution Terminals - Third Edition
 N RP 1637

Annotation

PURPOSE OF THE SYSTEM

This recommended practice describes a system for marking equipment used to store and handle bulk petroleum, alcoholblended petroleum and biodiesel products. The marking system described in this recommended practice does not cover aviation fuels. Marking systems for aviation fuels are described in API/IP Standard 1542, Identification Markings for Dedicated Aviation Fuel Manufacturing and Distribution Facilities, Airport Storage and Mobile Fuelling Equipment.

A uniform and easily understood identification system facilitates petroleum industry operations. Such a system helps to prevent mixing of multiple products, particularly gasoline with distillates, different grades of unleaded gasoline, gasoline containing alcohol or alcohol containing gasoline versus neat (undiluted) gasoline and distillates containing different sulfur contents.

The principal purpose of a marking system is to identify product transfer points for tank-truck loading and unloading at distribution terminals and retail outlets, and to prevent errors in product handling. Personnel who handle products may make the mistake of “cross-dumping” (commingling) products because these personnel rely on memory rather than on written records.

Gasoline blended to a required Reid Vapor Pressure (RVP) should always remain segregated from gasoline containing alcohol or alcohol containing gasoline as there is a potential for the commingling of the alcohol blend with the neat gasoline. This may result in a violation of volatility limits imposed on gasoline in certain areas of the country.

Ultra low sulfur distillates may be contaminated by higher level distillates and should be handled appropriately to prevent contamination. Increased risk of contamination could also be associated with truck transport from the terminal and at retail outlets. API Recommended Practice 1007, Loading and Unloading of MC 306/DOT 406 Cargo Tank Motor Vehicles provides guidelines for preventing contamination.