Class 900 Forged Carbon Steel Weld Neck, Raised-Face Flange for Schedule 160 Pipe

Class 900 A105N Weld Neck Raised-Face Flange for Schedule 160 Pipe

The Class 900 ASME A105N Normalized Forged Carbon Steel Weld Neck Raised-Face Flange for Schedule 160 Pipe, manufactured to ASME B16.5, provides a heavy-duty connection for demanding industrial pressure piping systems. Its tapered weld neck, normalized forged carbon steel construction, and raised-face sealing surface provide strength, durability, and dependable performance for heavy-wall Schedule 160 piping applications.

ASME A105N Normalized Forged Carbon Steel

Manufactured from ASME SA-105N / ASTM A105N forged carbon steel, this Class 900 weld neck flange undergoes a normalizing heat treatment that refines the steel grain structure and helps provide consistent mechanical properties. The “N” designation identifies the A105 carbon steel material as normalized.

A105N forged steel flanges are widely used in oil and gas, petroleum refining, petrochemical processing, chemical plants, power generation, manufacturing, utilities, and high-pressure industrial process piping systems.

Weld Neck Design for Schedule 160 Pipe

A weld neck flange incorporates a long, tapered hub that creates a gradual transition from the flange body to the connecting pipe. The flange is butt welded directly to the pipe, producing a strong permanent connection while helping distribute mechanical stresses through the tapered hub.

For Schedule 160 pipe, the flange bore can be selected or machined to correspond with the pipe wall thickness and inside diameter. Schedule 160 typically provides a substantially heavier wall and smaller inside diameter than Schedule 40 pipe of the same nominal size while maintaining the same outside diameter.

Class 900 Raised-Face Construction

The Class 900 designation is an ASME pressure class, not a maximum working pressure of 900 PSI. Actual allowable pressure depends on material, size, operating temperature, and applicable pressure-temperature ratings.

The raised-face (RF) design concentrates bolting force over the gasket seating area, helping establish a dependable seal between compatible mating flanges.

ASME B16.5 Flange Requirements

ASME B16.5 establishes applicable flange dimensions, facings, bolt patterns, tolerances, and pressure-temperature ratings.

When ordering, verify nominal pipe size, Schedule 160 bore, Class 900 rating, A105N normalized material, raised face, ASME B16.5 requirements, gasket, bolting, welding procedures, and service conditions.