Introduction
Flanges are critical components in any piping system, especially in medium and low pressure applications where reliability and cost-efficiency are key. For procurement engineers and industrial buyers, selecting the right flange is not just about matching dimensions; it involves understanding standards, material specifications, and quality control documentation. This guide provides a structured approach to procuring medium and low pressure flanges, focusing on practical considerations to ensure long-term performance and safety.
Flange Standards to Confirm
Before issuing an RFQ, verify which flange standard applies to your project. Common standards for medium and low pressure flanges include:
- ASME B16.5: Covers flanges from NPS 1/2 to NPS 24, with pressure classes 150, 300, 400, 600, 900, 1500, and 2500. For medium/low pressure, Class 150 and 300 are typical.
- EN 1092-1: European standard for flanges with pressure ratings PN 2.5 to PN 400. PN 6, 10, and 16 are common for low pressure systems.
- JIS B2220: Japanese standard for steel pipe flanges, with ratings 2K, 5K, 10K, etc., where 5K and 10K are used in low pressure applications.






