Do you really understand the meaning of the flange marking?

Do you really understand the meaning of the flange marking?

Flange of Pressure Transmitter: A Complete Guide to Markings

The flange of a  gauge pressure transmitter is a critical component for connection and sealing in industrial piping systems. Its markings directly reflect the flange’s specifications, material, design standards, and manufacturing/testing requirements.

These markings provide key references for installation and operation. Below is a detailed breakdown of flange markings:

1. Composition of gas pressure transmitter Flange Markings

Flange markings for smart pressure transmitter  are typically engraved on the outer ring or near the sealing surface, consisting of the following core information:

1.1 Nominal Diameter (DN)

Indicates the diameter of the piping the flange connects to, usually in millimeters (mm). For example, "DN100" means the flange is suitable for pipes with a nominal diameter of 100 mm.

1.2 Nominal Pressure (PN)

Represents the designed pressure the flange can withstand, commonly in megapascals (MPa) or pounds per square inch (psi). For example, "PN16" denotes a nominal pressure of 16 bar.

1.3 Material Code

The flange’s material determines its strength, corrosion resistance, and application environment. Common material codes include:

Carbon Steel: e.g., "A105" (forged carbon steel)

Stainless Steel: e.g., "304" or "316" (different types of stainless steel)

Alloy Steel: e.g., "F22" (low-alloy steel)

1.4 Standard Code

Flanges must be designed and manufactured in compliance with specific standards, such as:

ANSI/ASME B16.5: American standard flanges

EN 1092-1: European standard flanges

GB/T 9119: Chinese national standard flanges

1.5 Pressure-Temperature Rating

American standard flanges often include a "CLASS" marking (e.g., "CLASS 150") indicating a pressure rating of 150 pounds.

1.6 Heat Treatment Status

Some flanges are marked with heat treatment processes, such as "N" (Normalized) or "QT" (Quenched and Tempered).

2. Importance of Pressure Transmitter Flange Markings

Flange markings serve as a reliable basis for installation, acceptance, and long-term maintenance, with the following key functions:

Ensure Compatibility: Nominal diameter and pressure rating allow installers to quickly verify if the flange matches the piping and equipment.

Identify Material Performance: Material codes directly determine the flange’s mechanical properties and corrosion resistance, preventing failures caused by improper material selection.

Meet Standard Requirements: Standard codes guarantee the flange adheres to relevant specifications during design and manufacturing, ensuring quality and performance.

Traceability Management: Markings provide basic product information, facilitating future maintenance, replacement, or quality issue tracing.

3. Differences Across Countries and Industries

Flange marking requirements vary by country and industry worldwide. Examples include:

International Standardization: ISO standard flanges typically use PN markings, with common pressure ratings such as PN10, PN16, and PN25.

American Standard Flanges: Utilize CLASS markings (e.g., CLASS 150, CLASS 300) with a wide pressure-temperature range.

Japanese Standard Flanges: Follow "JIS" (Japanese Industrial Standards), with markings including pressure rating and material (e.g., 10K SUS304).

4. Common Issues with pressure transmitter HART Flange Markings

Faded or Missing Markings: Markings may become illegible due to corrosion or wear after long-term use—regular inspections and documentation are recommended.

Misinterpretation: Differences in marking conventions can lead to misreading or misuse, requiring special attention to standard variations in cross-border projects.

Incomplete Markings: Low-quality flanges may lack essential information—thorough checks are mandatory before installation.

Summary

Markings on EX pressure transmitter flanges are indispensable for industrial equipment installation and maintenance, embodying the flange’s specifications, material, and design standards. Accurately interpreting these markings in engineering practice effectively ensures system safety, reduces failure risks, and facilitates future maintenance and replacement. With technological advancements, digital and intelligent marking formats will further enhance the flange’s application efficiency in complex industrial environments.