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ANSI/ASME A13.1 Standards & How to Order

Standards reference, pipe marker buying guide, and ordering information.

ANSI/ASME A13.1 Standards & How to Order

This guide explains the ANSI/ASME A13.1-2020 standard for pipe marker identification and helps you understand what you need to properly mark your piping systems. The standard establishes requirements for marker size, letter height, color, legend, directional arrows, and placement to ensure safety and compliance.

About ANSI/ASME A13.1-2020

Over a century ago, the American Society of Mechanical Engineers (ASME) recognized the need for standards in identifying piping systems. The current ANSI/ASME A13.1-2020: Scheme for the Identification of Piping Systems establishes six requirements for proper identification. The 2020 update includes new pipe diameter and letter height requirements, guidelines for marking abandoned pipes, and optional use of GHS (Global Harmonized System) pictograms.

Six Requirements for Proper Pipe Identification

  1. Marker size (determined by pipe diameter)
  2. Letter height (for visibility and viewing distance)
  3. Color (indicates the type of hazard)
  4. Legend (the wording on the marker)
  5. Directional arrow (shows flow direction)
  6. Placement (positioning for visibility)

Table 1: Marker and Letter Size References

Pipe Outside Diameter (Including Insulation) Color Field Length Letter Height
0.7" - 1.3" (18 - 33 mm) 8" (203 mm) 0.5" (13 mm)
1.4" - 2.4" (34 - 61 mm) 8" (203 mm) 0.7" (19 mm)
2.5" - 6.7" (62 - 170 mm) 12" (305 mm) 1.3" (32 mm)
6.8" - 10" (171 - 254 mm) 24" (610 mm) 2.5" (64 mm)
Over 10" (Over 254 mm) 32" (813 mm) 3.5" (89 mm)

Why? The marker size and letter height are determined by the overall pipe diameter including insulation. Letter height requirements are designed for optimum visibility and adequate viewing distance. Color field requirements can be met by including an arrow or arrow banding tape.

Table 2: Color Designations

Fluid Service Category Color Scheme
Fire Quenching Fluids Black letters on yellow background
Toxic And Corrosive Fluids Black letters on red background
Flammable Liquids Black letters on red background
Combustible Fluids Black letters on yellow background
Potable, Cooling, Boiler Feed, Other Water Black letters on green background
Abandoned Pipes Black letters on white background with black border
Compressed Air Black letters on blue background
Defined By User (4 additional categories) User-defined

What do the colors signify? Marker colors help identify the inherent danger of piping contents. There are ten color designations: seven standard and four user-defined.

Table 3: Location of Identification Markers

Placement Location Frequency/Requirements
On Straight Pipes Every 25 - 50 feet
At Each Side of Floor or Wall Pass-through At each penetration point
Adjacent To Valves & Flanges At each valve and flange
Adjacent To Directional Changes At each direction change

Where do markers go? Marker placement is required to assure visibility. Position markers so they are visible from a normal approach point. Where pipes are above or below normal vision, place lettering above or below the pipe's horizontal centerline.

Table 4: Standard GHS Pictograms

The use of GHS pictograms or symbols is optional. Where piping is connected to containers labeled in accordance with GHS requirements, a corresponding label including pictograms may be provided.

Standard GHS Pictograms: Health Hazard | Flammable | Harmful | Toxic | Oxidizing | Compressed Gas | Corrosive | Explosive | Environment Hazard

Abandoned Piping

The new 2020 standard recommends marking abandoned piping left in place. These should be marked with a safety white marker with black letters and include a black border. If the piping is protected by pressurized fluid or contains residual hazardous materials, the legend should indicate that.

Legend Determination

The wording can be the full or abbreviated name of the system content. The standard indicates that legends shall be "brief, informative, pointed, and simple for greatest effectiveness." The legend should have sufficient additional details such as temperature, pressure, etc., as necessary to identify the hazard.

Why Use Directional Arrows?

Arrows show the directional flow of piping contents. If flow can be in both directions, arrows in both directions should be used. Kolbi's Wrap-Around Markers include integrated arrows. Adhesive Markers comply when used with Arrow Banding Tape or Individual Arrows.

Pipe Marker Buying Guide

Choose the marker type that best suits your application, environment, and budget.

Feature Adhesive Pipe Markers Wrap-Around Pipe Markers High-Performance Pipe Markers
Application Method (Under 6" OD) Stick-on with Permanent Adhesive Snap-on Precoiled Precoiled with Adhesive Strip
Application Method (Over 6" OD) Permanent Adhesive Precoiled or Nylon Straps Precoiled or Stainless Steel Straps
Surface Preparation Clean, Dry Surface Any Surface Any Surface
Application Temperature Above 50°F Above 0°F Above 32°F
Outdoor Durability Good Very Good Great
UV Protection Good Good Great
Expected Outdoor Life Up to 3 years Up to 5 years Up to 8 years
Expected Indoor Life Indefinite Indefinite Indefinite
Integrated Arrows Available with or without Yes Yes
Material Vinyl Semi-rigid Vinyl Polyester
Service Temperature Range -40°F to 180°F (-40°C to 82°C) -40°F to 180°F (-40°C to 82°C) -40°F to 248°F (-40°C to 120°C)
ANSI/ASME A13.1 Compliant Yes (with arrow or arrow tape) Yes Yes
Visibility Front view only 360° view 360° view
Abrasion Resistance Good Very Good Great
Chemical Resistance Good Good Great
Available Colors All A13.1 Colors All A13.1 Colors All A13.1 Colors
Custom Wording Available Yes Yes Yes
Custom Colors Available Yes Yes Yes
Custom Size Available Yes Yes Yes
Application Time 2+ Minutes 5-10 Seconds 20-30 Seconds

How to Order

Step 1: Determine Your Piping Size
Measure your pipe's outside diameter (including any insulation). Use Table 1 to find the required marker size, color field length, and letter height.

Step 2: Choose Your Legend (Wording)
Select from standard legends (available in the full catalog) or specify custom wording if needed. Ensure your wording clearly identifies the fluid service and any hazards (temperature, pressure, etc.).

Step 3: Select Your Color
Use Table 2 to select the color that corresponds to your fluid service category.

Step 4: Choose Your Marker Type
Reference the Pipe Marker Buying Guide above to select the best marker type for your application (Adhesive, Wrap-Around, or High-Performance).

Step 5: Decide on Arrows
Determine whether you need arrows to indicate flow direction. For Adhesive Markers, purchase Arrow Banding Tape or Individual Arrows separately.

Step 6: Place Your Order
Contact Kolbi Pipe Markers with your requirements. We offer no setup charges or minimums—you get exactly what you need, when you need it.

Key Notes

  • No setup charges or minimum order quantities
  • Combine quantities across products for best pricing
  • Custom markings available with fast turnaround
  • All standard products are ANSI/ASME A13.1 compliant
  • Submittal samples available for approval before production

Contact Information

Kolbi Pipe Markers
Email: sales@kolbipipemarkers.com
Phone: 800-499-8450
Website: www.kolbipipemarkers.com

Our team is ready to help you select the right markers for your project and ensure full compliance with ANSI/ASME A13.1 standards.