\”AMSE B16.5\” actually refers to the industrial pipe flange standard formulated and maintained by the American Society of Mechanical Engineers (ASME), and it is the core representative standard of the \”American Pipe Flange System\”. Generally, ASME B16.5 is applicable to pipes with an NPS of 24 inches and below; for larger diameters (NPS 26 to 60 inches), the ASME B16.47 standard needs to be used.
- Covered flange types: including butt-weld flanges, socket-weld flanges, threaded flanges, slip-on flanges, lap-joint flanges, and blind flanges, among others.
This is one of the most widely used standards for pipe flanges and flange components in the global petrochemical, chemical, power, oil and gas industries.
The core definition and application scope of the standard
The ASME B16.5 standard, officially known as \”NPS 1/2 to NPS 24 Metric/American Standard Pipe Flanges and Flange Fittings\”, mainly stipulates:
- Size range: Covers flanges with nominal pipe diameters (NPS) ranging from 1/2 inch to 24 inches.
- Pressure rating: Defines seven pressure classes (Classes) of 150, 300, 400, 600, 900, 1500 and 2500. Each class corresponds to different maximum allowable working pressures and changes with temperature.
- Specification content: Details the pressure-temperature ratings, materials, dimensions, tolerances, markings and tests required for the flanges.
150th level Maximum pressure (100°F / 38°C): 285 psi Application: General water pipes, low-pressure steam, HVAC systems
300 series Maximum pressure (100°F / 38°C): 740 psi Application: Medium-pressure steam, industrial water supply, chemical processing
600th grade Maximum pressure (at 100°F / 38°C): 1480 psi Application: High-pressure steam, oil and gas pipelines, refineries
Pressure rating of 900 psi and above (100°F / 38°C): 2200 psi and above. Applications: Heavy industry, power plants, offshore platforms, nuclear power plants.
Post time: Jan-27-2026
