Pressure vessels are essential in industries like oil and gas, chemical processing, and power generation. These containers must withstand extreme pressures, making safety a top priority. One often-overlooked yet crucial aspect of safety is permanent flange marking. Proper identification ensures traceability, compliance, and accident prevention.

The Importance of Flange Marking in Pressure Vessels

Flanges connect pipes, valves, and other components in pressure vessels. Permanent marking provides critical information, including:

Material grade (e.g., ASTM A105, A182)

Pressure-temperature ratings (e.g., Class 150, 300)

Manufacturer details

Heat numbers and batch codes

Without clear, permanent markings, misidentification can lead to catastrophic failures.

Safety Risks of Poor or Missing Flange Markings

Material Mismatch – Using the wrong flange material (e.g., carbon steel instead of stainless steel) can cause corrosion or rupture under pressure.

Incorrect Pressure Ratings – Installing a flange rated for lower pressure than required can result in explosions.

Traceability Issues – In case of a failure, unmarked flanges make it difficult to investigate the cause.

Non-Compliance with Regulations – Standards like ASME, API, and PED require permanent markings for safety and accountability.

Best Practices for Permanent Flange Marking

To ensure safety and compliance, manufacturers should use durable marking methods such as:

Laser engraving – Precise and resistant to wear.

Dot peen marking – Deep, permanent indentation.

Electrochemical etching – Corrosion-resistant and legible.

Markings should be placed in a visible location and withstand harsh environments (heat, chemicals, and abrasion).

Conclusion

Permanent flange marking is not just a regulatory requirement—it’s a lifesaving practice in pressure vessel manufacturing. Proper identification prevents accidents, ensures compliance, and enhances traceability. By investing in reliable marking techniques, manufacturers can uphold safety standards and avoid costly failures.