Flange Pressure Rating Classes (150# to 2500#)
Engineering definition, metallurgical mechanisms, standard testing specifications, and manufacturing guidelines for closed-die forgings up to 50 kg.
Quick AnswerFeatured
Standardized pressure-temperature designations (Classes 150, 300, 400, 600, 900, 1500, 2500) that define the allowable operating pressure of a flange across temperatures.
Technical Explanation & Metallurgical Principles
Flange pressure classes correlate directly to wall thickness, bolt circle diameter, and flange ring stiffness. As operating temperature rises, allowable working pressure drops. For example, a Class 150 carbon steel flange rated for 285 psig at ambient temperature has its allowable pressure reduced to only 170 psig at 500°F (260°C).
Key Engineering Specifications & Parameters
| Technical Parameter / Metric | Engineering Benchmark / Value |
|---|---|
| ASME Classes | 150#, 300#, 400#, 600#, 900#, 1500#, 2500# |
| Metric Equivalents | PN 20, PN 50, PN 64, PN 100, PN 150, PN 250, PN 420 |
| Governing Table | ASME B16.5 Table 2 Pressure-Temperature Ratings |
Application at Jayesh Forge (Rajkot Plant)
Jayesh Forge manufactures ASME B16.5 flanges across all pressure classes strictly up to 50 kg max piece weight in Rajkot, Gujarat.
Related Materials, Standards & Products
Applicable Material Grades
Related Metallurgical & Testing Terms
ASME B16.5 Pipe Flanges Standard
The definitive American standard covering pressure-temperature ratings, materials, dimensions, tolerances, marking, and testing for pipe flanges NPS 1/2 through NPS 24.
Weld Neck Flange (WN Flange)
The premier high-integrity forged flange configuration featuring a long, tapered circular hub that butt-welds seamlessly to process pipe.
Blind Flange (ASME B16.5 & DIN)
A solid circular forged disk with bolt holes but no central bore, used to terminate the end of a piping run, valve nozzle, or pressure vessel inspection opening.
Questions Regarding Flange Pressure Rating Classes (150# to 2500#)
No, a Class 300 ASTM A105 flange can withstand 740 psig at ambient temperature (-29°C to 38°C); '300#' is a standardized class designation, not a cold pressure ceiling.
Request a Forging Quote with Flange Pressure Rating Classes (150# to 2500#) Compliance
Our Rajkot metallurgy desk is ready to review your technical drawings, testing protocols, and delivery schedules for custom closed-die forgings strictly up to 50 kg.