Titles should be stenciled or lettered on pipe (or covering) where the view is unobstructed, such as on the lower quarters. Lettering in this position is unlikely to be obscured by dust collection or mechanical damage. Titles should be in black or white ONLY and be clearly visible from operating positions, especially those next to control valves.

Use stencils with standard-size letters, as shown in table 1-2. For pipelines smaller than three quarters of an inch in diameter, use securely fastened metal tags with lettering etched or filled in with enamel. Apply titles with uppercase letters and Arabic numerals whenever applicable.

PRIMARY COLOR WARNINGS should be a single color, applied as a BAND (or BANDS), that completely encircle(s) the piping system. They are located on the piping system immediately next to all operating accessories, such as valves, regulators, strainers, and vents. The bands should be painted throughout the system at convenient intervals where branch lines join the system, where the system passes underground or through walls, and at any other conspicuous place where warnings are required. All piping and covering of an entire system, excluding straps, hangers, and supports, may be painted with the primary color warning. When this is done, DO NOT paint color bands of any kind on the system.

A colored ARROW should be used next to each primary color warning applied to a piping system to indicate the normal direction of flow of the material in the system. A double-headed arrow is used on lines subject to reverse flow. The color of arrows can be the same as the primary warning when bands are

Table 1-2. - Size of Stencil Letters

used - black or white. (Refer to fig. 1-17 for identification of piping systems.)

MARKING COMPRESSED GAS CYLINDERS

Compressed gas cylinders used throughout the Department of Defense are of a standard color code. The material within is shown by a written title in two locations diametrically opposite and parallel to the longitudinal axis of the cylinder. Cylinders having a background color of yellow, orange, or buff have the title painted black. Cylinders having a background color of red, brown, black, blue, gray, or green have the title painted white.

A primary color warning relates to the primary hazard of the material. These colors appear as a circular band on piping systems and as main body, top, or band colors on compressed gas cylinders.

Figure 1-17. - Identification of piping system.