Improving a facility&#;s safety and efficiency often is as simple as using proper valve labeling and identification practices. Even though valves may not be a main component of heavy machinery, they can do quite a bit of damage if someone opens the wrong valve. The other benefit of using the appropriate valve labeling and identification practices are significant reductions in the risk of spills, accidents, and injuries caused by the valves and pipes in a facility.

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If you want to improve the safety of your facility by adding valve labels for the first time, or if you are looking to improve your valve labeling and identification processes, there are a few standards and practices you should follow including

Read on to learn more about the proper valve labeling and identification processes, standards, and practices.

1. Determine Which Parts of the Valve Need to be Labeled

Valve labeling and identification can be quite an undertaking because there may be hundreds of control valves and thousands of manual valves within a facility or refinery. The challenge is to properly label and identify growing numbers of valves that require repair, maintenance, and validation. Not only do facilities and refineries have several types of valves such as solenoid, gate, plug, butterfly, pinch, diaphragm, ball, and globe, but they also have valves that require identification on several different parts including the body of the valve, bottom of the valve, and underside of the valve.

When determining which parts of the valve need to be labeled, keep in mind that the objective of the tags and labels is to ensure safe operation. All tags and labels should be placed in locations that are visible to everyone. As such, you should not place tags or labels on valve handles or wheels. The Department of Energy clearly states that labels for valve components &#;should be permanently attached to the components (e.g., attached to the valve yoke, not to a removable part such as a handwheel) in a way that will not interfere with the normal operational use or testing of the component. Valves operated by reach rods or chains, or other remotely operated components, should have an additional label installed at the operating device. Labels for chain operators should be attached to a small piece of tubing through which the chain passes, so the label always remains at the bottom of the chain loop. If the valve is difficult to be seen from the operating location, the label should indicate the open and close direction for the chain or other operator.&#;

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2. Know and Understand Valve Labeling Standards

Unfortunately, the American Society of Mechanical Engineers (ASME) and the American National Standards Institute (ANSI) do not explicitly require valve tag placement. However, they do have codes requiring proper marking of piping systems, and those codes typically apply to valves because valves are part of piping systems. As such, valve tags use the ANSI/ASME A13.1 standard for color coding (a pipe labeling standard followed in the industry for valve labeling purposes due to the lack of a separate standard for valve labeling). The tags must identify the valve and usually do so by including the valve number. The tag also typically identifies the valve type and system of which the valve is a part. It&#;s important to note that the type of valve specified is dependent upon its function rather than on the design of the valve. Additionally, valves such as ball and gate valves are described according to their design and usually are not specified on the valve tags.

The ANSI/ASME A13.1 color code includes six standard colors and four user-defined colors. The six predefined colors identify types of pipe contents, and the standards provide definitions to help facilities use the correct colors. The user-defined colors, on the other hand, are defined by individual facilities using the standard, and the facilities must document the definitions and train workers. The color code is as follows

• Fire-quenching fluids: White text on red background
• Toxic or corrosive fluids: Black text on orange background
• Flammable or oxidizing fluids: Black text on yellow background
• Combustible fluids: White text on brown background
• Other water: White text on green background
• Compressed air or other gases: White text on blue background
• User-defined: White text on purple background
• User-defined: Black text on white background
• User-defined: White text on gray background
• User-defined: White text on black background

There are some points of confusion that arise from the ANSI/ASME A13.1 color code. First, facilities question the difference between flammable and combustible. According to the standard, if the material is a vapor or produces a vapor that could ignite and burn in air, it is flammable. Other materials that could pose a fire hazard fall into the combustible category.

Sometimes facilities question how to label pipes and vales that fall into multiple categories, as is the case then flammable gases also are toxic. Generally, each facility makes the decision. Some facilities identify the hazard type that is more significant to them specifically and use the color for that particular hazard; other facilities use a user-defined color to identify combinations of hazards.

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3. Utilize Proper Tag Placement

Label and tag placement on pipes and valves is critical to facility safety. Facilities typically follow four general rules about placing pipe labels and valve tags; these rules follow recommendations from ANSI.

1. Place pipe labels at all directional changes
2. Place pipe labels on both sides of the entry points through floors and walls
3. Place valve tags next to all valves and flanges
4. Place pipe labels at 25-50 foot intervals on straight runs

It is best to place valve tags in locations where workers will clearly see the pipe contents and valve information prior to opening the valve itself. It is important never to attach valves to valve stems or actuators. In many cases, tags are attached to valves using plastic or metal ties.

4. Use the Proper Type of Valve Tag

Valve tags can be made of a variety of materials including plastic, metal, wood, or paper. Metal valve tags are popular because of their durability. They are available in a variety of metal types including stainless steel, aluminum, and brass. Stainless steel tags are ideal for environments that include water and chemicals because they resist rusting and corroding. Aluminum tags are light weight and capable of being engraved. They are a good choice for environments that have low temperatures; however, they are not as strong in extremely hot environments. Brass tags are strong and may be used in high-temperature situations and environments that are corrosive.

Tags also vary in size from small circles to large squares, depending on the amount of information they need to contain. Of course, facilities need to select the proper type of tag for the valve environment in which it will be placed. Thus, safety managers often use multiple types of tags throughout their facilities. They also often choose tags that follow the pipe color schemes to have a consistent labeling system that visually communicates information to workers.

There are many considerations to make when labeling and identifying valves and pipes in a facility. Safety manager should determine which parts of the valve need to be labeled, know and understand valve labeling standards including ANSI/ASME A13.1, utilize proper valve tag placement, and use the proper type of valve tags throughout their facility.

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How To Read Ball Valve Markings

Figure 1: A ball valve marked with DN20, meaning its port size is 20 mm.

A ball valve's valve label helps a user quickly identify important information about the ball valve. The user can use this information to determine if the particular valve suits an application. These labels are either stamped onto the outside of the valve's body or found on a tag connected to the valve (e.g., connected to the handle or printed on the handle). Not all information on a label is easily understood, however. The following is an overview of the typical information on a ball valve label and how to interpret it.

Valve size

The valve's size (port size) is often marked in inches and/or millimeters.

• Inches: The valve is marked with a simple inch designation, for example, 1/2" or 3/4".
• Millimeters: The valve is marked with a DN (diameter nominal) followed by a number indicating the size in millimeters. For example, DN20 (Figure 1).

Body material

The body material designation indicates which material was used to create the valve's body. Some examples are:

• Stainless steel: Different markings indicate stainless steel 304 and 316.
  • 304 and 316 (Figure 2)
  • SS304 and SS316
  • CF8 and CF8M

Figure 2: The marking indicates this is a stainless steel electric ball valve.

• Plastics: Material markings for plastic ball valves are the plastics' standard abbreviations
  • PVC (Figure 3) and CPVC
  • ABS
  • PP
  • PTFE
  • PE & HDPE

Figure 3: The markings on this pneumatic ball valve indicate that it is made of PVC (A) and its size is DN40 (B).

• Brass and bronze
  • Brass: BS, BRS, CW617N
  • Bronze: BZ, BRZ, C
• WCB: Cast carbon steel. It is very common in ball valve manufacturing.

Mounting information

A specific marking on the valve can indicate that the ball valve has a standard ISO mounting configuration for mounting an actuator&#;for example, F04 and F05 (Figure 4 labeled A). Learn more in our article on ISO .

Pressure class

The valve's optimal pressure rating will often be marked in bar or PSI.

• Bar: The pressure in bar follows PN (pressure nominal)&#;for example, PN68.
• PSI: The pressure in PSI is simply marked. For example, PSI

WOG, CWP, & WSP

• WOG (Figure 4 labeled B) is an outdated mark that may appear on new ball valves and older ball valves. It means the ball valve is meant for water, oil, and gas applications.
• CWP indicates the valve's maximum working pressure between -29 °C and 38 °C (-20 °F and 100 °F). For example, CWP means the valve's maximum working pressure is PSI between these temperatures.
• WSP indicates the valve's maximum working pressure in steam applications. Sometimes, this is marked as SWP.

Figure 4: The markings on this electric ball valve indicate that this valve has a standard ISO mounting (A) and is suitable for water, oil, and gas applications (B).

Ratings for gas

A ball valve's gas rating differentiates indoor and outdoor gas applications.

• Indoor: 1/2 PSIG is for ball valves used in low-pressure applications. 5G is for higher-pressure systems such as gas piping.
• Outdoor: Common outdoor ratings for ball valves used in gas applications are CAN/CGA-3.16 and BRS125G. The former is a Canadian standard, and the latter is a U.S. standard. In Europe, a commonly used standard is BS EN 331.

Lead free

If the valve is marked with LF, no lead was used in its construction.

Figure 5: A lead-free ball valve

FAQs

What do the markings on a ball valve mean?

The most common markings indicate the ball valve's size. For example, DN40 indicates the ball valve has a 40 mm port.

What do the numbers on a ball valve mean?

The numbers on a ball valve often indicate its size and pressure rating. For example, 1/2" indicates the valve's port size and PN68 indicates its maximum working pressure in bar.

For more information, please visit DN Gate Valve.