Text identifying the pipe’s exact contents and arrows indicating the direction of flow leave little room for error or guessing in operations. |
The next area of note revolves around color coding. The standard provides a recommended color scheme that assigns different colors for various types of sludge, gas, water, chemicals, and other things like plumbing drains and vents. While color coding aids workers in the identification of a pipe’s contents, it is not sufficient on its own. This may be, in part, because some colors are used for more than one content type. Red, for example, is used to identify fuel oil/diesel, natural gas, sludge gas, and fire mains. Here there is an obvious conflict: Both contents that can make a fire worse and those that can quench a fire may be identified with the same color. Using text to clearly identify each pipe’s contents is essential for safety.
When marking pipes, it’s important to do it correctly, yet there is some contradiction about exactly how pipes should be marked. This is the final nuance. Section 54.5 states that “the contents and direction of flow shall be stenciled on the piping in a contrasting color.” Meanwhile, Section 57.25 states: “All piping containing or transporting corrosive or hazardous chemicals shall be identified with labels.” So what should be done? With the advancement in label durability and longevity of materials, many authorities will accept labels in place of stenciled markings.
Water Works Facilities
The 2012 edition of the Recommended Standards for Water Works also provides guidance for pipe marking. While this standard suggests including the name of the chemical or liquid as well as the direction of flow on labels, it does not provide any guidance for how often a pipe should be labeled. It does, however, include a comprehensive color code and specific requirements for feed equipment.
First, this standard separates color codes into three categories: water lines, chemical lines, and other. When colors are too similar to easily differentiate, the standard suggests using a six-inch band every 30 inches to help workers identify each pipe’s contents.