Class 2500 Flanges

Kalp Alloys is a leading manufacturer and supplier of Class 2500 Flanges (also known as 2500 lb flanges or 2500# flanges) conforming to ASME B16.5 standard. We supply Class 2500 pipe flanges in all standard types — Slip-On (SOF), Welding Neck (WNF), Socket Welding (SWF), Threaded (THDF), Lap Joint (LJF), and Blind (BLF) — in sizes ranging from NPS 1/2″ to NPS 12″. Our flanges are manufactured in a wide range of materials including Stainless Steel (SS 304, 316L, 321), Carbon Steel, Alloy Steel, Duplex, and Nickel Alloys to meet the most demanding industrial requirements.

A Class 2500 flange is a pressure-class designation under the ASME B16.5 standard (Steel Pipe Flanges and Flanged Fittings). The “2500” refers to the pressure class — the highest pressure class defined in ASME B16.5, engineered for the most extreme high-pressure and high-temperature piping applications. Class 2500 flanges are rated at approximately 6170 psi (425 bar) at ambient temperature (38°C) for carbon steel.

They are used in the most critical and demanding service conditions — including ultra-high-pressure hydraulic systems, deep-sea oil & gas exploration, high-pressure chemical reactors, and supercritical steam pipelines — where no lower pressure class can meet the design requirements. As the heaviest and most robust flange class in ASME B16.5, Class 2500 flanges represent the pinnacle of pressure-containing capability in industrial piping.