HomeStandardsASME B16.47

Valve Standard Reference

ASME B16.47

American

Large Diameter Steel Flanges NPS 26 Through NPS 60 Metric/Inch Standard

ASME B16.

What is ASME B16.47?

ASME B16.47 (Large Diameter Steel Flanges NPS 26 Through NPS 60 Metric/Inch Standard) is an industrial valve standard issued by American Society of Mechanical Engineers (ASME). Covers carbon steel and alloy steel welding-neck, slip-on, blind, threaded, socket-welding, lap-joint, and orifice flanges in NPS 26" through NPS 60", pressure classes 75, 150, 300, 400, 600, and 900.

Issuing Body:
American Society of Mechanical Engineers (ASME)
Category:
design

Overview - ASME B16.47

ASME B16.47 covers large-diameter steel flanges for pipe sizes NPS 26" through NPS 60" in pressure classes 75 through 900, filling the size gap above ASME B16.5 (which only covers up to NPS 24"). The standard provides two distinct flange dimension series: Series A (based on the former MSS SP-44 large pipe flange standard) and Series B (based on the former API 605 standard). The two series have different bolt hole patterns, flange dimensions, and weights, so Series A and Series B flanges are NOT interchangeable - this is critically important for procurement and field installation of large-bore pipeline and industrial valves.

Scope

Covers carbon steel and alloy steel welding-neck, slip-on, blind, threaded, socket-welding, lap-joint, and orifice flanges in NPS 26" through NPS 60", pressure classes 75, 150, 300, 400, 600, and 900. Series A dimensions follow MSS SP-44; Series B dimensions follow the superseded API 605. Applicable to large-bore pipeline mainline flanges, large compressor station piping, terminal storage piping, and large chemical plant piping.

Vajra Industrial Solutions manufactures and supplies valves engineered to comply with ASME B16.47, each delivered with ASME B16.47 Series designation (A or B) on documentation and marking and Pressure class marking on flange as standard.

Need ASME B16.47 compliant valves?

Share your requirements — we supply valves to ASME B16.47 with full certification documentation, quoted in 24 hours.

Applicable Valve Types

Gate Valves - large bore (NPS 26" and above) with flanged ends

Ball Valves - large bore trunnion-mounted with flanged ends

Butterfly Valves - large bore double-flanged

Check Valves - large bore flanged

Applicable Pressure Classes

Class 75 (Series A)Class 150Class 300Class 400Class 600Class 900

Key Requirements - ASME B16.47

01.

Two non-interchangeable series: Series A (MSS SP-44 heritage) and Series B (API 605 heritage)

02.

Pressure classes covered: Class 75 (Series A only), 150, 300, 400, 600, 900

03.

Material groups aligned with ASME B16.5: Groups 1.1 through 2.3 for P-T ratings

04.

Flange type: welding neck (most common for large bore), blind, slip-on, ring-type joint

05.

Bolt holes: different count and diameter between Series A and B for same class/size - never mix series

06.

Maximum size: NPS 60" Class 300 in Series A; NPS 60" Class 150 in Series B

07.

All dimensions in both inch and metric (dual dimensioning)

08.

Material marking: class, size, material designation, heat number, and standard (B16.47) on flange face

Testing Requirements - ASME B16.47

Dimensional inspection per ASME B16.47 Series A or B tables

Hydrostatic shell test at 1.5× rated pressure for flanged valves

PMI verification for alloy steel and stainless steel flanges

Documentation Required for ASME B16.47 Compliance

ASME B16.47 Series designation (A or B) on documentation and marking

Pressure class marking on flange

Material Test Reports (MTR) per EN 10204 3.1

Dimensional inspection report confirming series and class compliance

Related Standards

Browse ASME B16.47 Compliant Valves

All Standards

Part of the Vajra Valve Standards Library
Reviewed by Valve Standards Engineering, Vajra Industrial SolutionsDiscipline: Industrial Valve Standards & ComplianceLast reviewed: 20 June 2026

Connected Engineering

Need ASME B16.47 Compliant Valves?

We supply valves to ASME B16.47 with full certification documentation. Share your requirements for a 24-hour quote.