1. OBJECT AND SCOPE
1.1 This Standard is intended to establish a common system to assist in identification of hazardous materials conveyed in piping systems and their hazards when released in the environment.
1.2
This scheme concerns identification of contents of piping systems in industrial and power plants. It is also recommended for the identification of piping system used in commercial and institutional installations, and in buildings used for public assembly. It does not apply to pipes buried in the ground nor to electrical conduits.
1.3
Existing schemes for identification shall be considered acceptable if such schemes are described in writing and implemented so that the using facility can demonstrate that the basic concerns outlined in this Standard are being met. For example, petroleum refineries and primary chemical manufacturing plants in which hazardous work permit systems and emergency procedure manuals are utilized, wherein effective methods for the identification of pipe contents have been established and wherein employees are trained as to the operation and hazards of the piping systems, shall be considered as meeting the requirements of this Standard.
2. DEFINITIONS
2.1 Piping Systems
For the purpose of this Standard, piping systems shall include pipes of any kind and, in addition, fittings, valves, and pipe coverings. Supports, brackets, or other accessories are specifically excluded from applications of this Standard. Pipes are defined as conduits for the transport of gases, liquids, semiliquids, or fine particulate dust.
2.2 Materials Inherently Hazardous
2.2.1 Flammable or Explosive.
This classification includes materials which are easily ignited. It includes materials known as fire producers or those creating an explosive atmosphere.
2.2.2 Chemically Active or Toxic.
This classification includes materials which are corrosive, or are in themselves toxic or productive or poisonous gases.
2.2.3 At Temperatures or Pressures.
This classification includes materials which when released from the piping would have a potential for inflicting injury or property damage by burns, impingement, or flashing to vapor state.
2.2.4 Radioactive.
This classification includes those materials which emit ionizing radiation.
2.3 Materials of Inherently Low Hazard
This classification includes all materials which are not hazardous by nature, and are near enough to ambient pressure and temperature that people working on systems carrying these materials run little risk through the release of these materials.
|
2.4 Fire Quenching Materials
This classification includes sprinkler systems and
other piped fire fighting or fire protection equipment. This includes water (for fire fighting),
foam, CO2, Halon, etc.
3. METHOD OF IDENTIFICATION
3.1 Legend
This Standard considers legend to be primary and explicit for
identification of contents. Positive identification of the contents of a piping system shall be
by lettered legend giving the name of the contents in a full or abbreviated form. Arrows shall be used to indicated direction of flow. Contents Shall be identified by legend with sufficient additional details such as temperature, pressure, etc., as necessary to identify the hazard.
Legend shall be brief, informative, pointed, and simple for greatest effectiveness. Legends shall be applied close to valves of flanges and adjacent to to changes in direction, branches, and where pipes pass through walls or floors; and at intervals on straight pipe run efficient for identification. In any situation, the number and location of identification markers shall be based on the particular piping system.
3.2 Color
Color should be used to identify the characteristic hazards of the contents. Color should be displayed on, or contiguous to, the piping by any physical means, but its use shall be in combination with legend. Color may be used in continuous, total length coverage or in intermittent displays.
3.3 Visibility
Attention shall be given to visibility with reference to pipe markings. Where pipe lines are located above or below the normal line of vision, the the lettering shall be placed below or above the horizontal centerline of the pipe.
3.4 Type and Size of Letters
Contrast shall be provided between color field and legend for readability. The following page gives recommendations for color of legend on various color fields covered in this Standard. Use of letters of standard style, in sizes 1/2 in. and larger, is recommended. For identification of materials in pipes of less than 3/4 in. diameter, and for valve and fitting identification, the use of a permanently legible tag is recommended.
3.5 Unusual or Extreme Situations
When the piping layout creates or occurs in a limited area of inaccessability or of extreme complexity, such segments of layouts may require substitute techniques to achieve positive identification. Use of substitute techniques shall be limited to such segments and shall not deviate from the concept of identification.
NEXT PAGE |
