Benefits of Pipe Marking for Water Treatment Facilities
Two major pipe marking standards have been developed by representatives from 10 U.S. states and one Canadian province.
They are: Recommended Standards for Wastewater Facilities and Recommended Standards for Water Works.
These standards are part of a set of standards called the 10 States Standards. Over time other states have either adopted these standards or used them as a baseline for their own standards. Each standard provides guidelines on how pipes should be marked to improve safety and efficiency.
Basic Pipe Marker Elements
In general, there are five elements that make an effective pipe label. These elements are:
- Color coding: Provides a means for workers to quickly identify the general pipe contents and potential hazards.
- Text: Identifies the pipe’s exact contents and may also display other hazards like temperature or pressure.
- Arrows: Indicate the direction of flow, including when contents may flow in either direction.
- Label placement: Ensures people will see the label and be able to access the information they need with minimum effort.
- Size: Choosing the right size label and text ensures pipe markers can be read.
The first four elements are covered in the 10 State Standards, and guidelines for the fifth can be found in another standard: ASME A13.1 (2015), which is maintained by the American Society of Mechanical Engineers.
There are some important nuances in the 2014 Edition of the Recommended Standards for Wastewater Facilities. Like most pipe marking standards, this standard provides some guidance on label placement, stating that pipes must be labeled every 10 feet (3 meters). However, there is a unique requirement not found in other standards: At least two labels must be in every room, closet, and piping case.
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.
Clearly labeling pipes can improve safety and efficiency in water treatment facilities.
For bulk storage of liquid chemicals, day tank entry points must be labeled with the name of the chemical they contain. In addition, the standard recommends labeling and color coding feed lines to improve recognition.
Learn more about the 10 States Standards and the suggested color codes with the Water Treatment Pipe Marking Guide by Graphic Products.
Read more: Water World