ASME B16.47 Large Diameter Flanges – Series A & Series B
Large Diameter Flanges for Industrial Piping
Large diameter piping systems require flange connections designed specifically for larger nominal pipe sizes. ASME B16.47 provides dimensional and rating requirements for large diameter steel flanges.
Vandan Alloys manufactures and supplies ASME B16.47 large diameter flanges for industrial piping, process plants, energy projects and other engineering applications.
What Is ASME B16.47?
ASME B16.47 is a standard covering large diameter steel flanges.
It applies to flange sizes from:
NPS 26 through NPS 60
The standard includes dimensional requirements, pressure-temperature ratings, materials and other requirements applicable to the flanges within its scope.
For large diameter flange enquiries, the complete requirement should include NPS, pressure class, flange type, material and series, where applicable.
ASME B16.47 Series A & Series B
ASME B16.47 includes two flange series:
Series A
Series B
The two series can have different dimensional characteristics, including differences in outside diameter, bolt arrangement and flange geometry.
Therefore, Series A and Series B should not be treated as interchangeable simply because they have the same NPS and pressure class.
The required series should be confirmed from the project specification or engineering requirement.
ASME B16.47 Series A Flanges
Series A large diameter flanges are commonly specified for large piping and equipment connections where the Series A configuration is required.
The flange dimensions and bolt-hole arrangement are manufactured according to the applicable ASME B16.47 requirements.
Series A requirements should be identified clearly when preparing a purchase order or enquiry.
ASME B16.47 Series B Flanges
Series B provides another dimensional configuration for large diameter steel flanges covered by ASME B16.47.
Series B can have a different bolt arrangement and dimensional profile compared with Series A.
For replacement requirements, customers should verify the existing flange dimensions and required series before ordering.
ASME B16.47 Size Range
Large diameter flange sizes covered by ASME B16.47 include:
NPS 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58 and 60, subject to the applicable configuration and pressure class.
The exact dimensions depend on the NPS, pressure class, series and flange configuration.
ASME B16.47 Pressure Classes
Large diameter flanges can be specified in pressure classes such as:
Class 150, Class 300, Class 400, Class 600, Class 900 and Class 1500, where applicable to the particular flange size and series.
Not every class is applicable to every size or configuration.
The applicable ASME B16.47 requirements should always be checked for the selected NPS and pressure class.
Large Diameter Flange Types
Large diameter flange requirements can include configurations such as:
Weld Neck Flanges
Used for welded pipe connections and commonly considered for demanding piping systems.
Blind Flanges
Used to close large-diameter piping, equipment nozzles or pipeline sections.
Other configurations may be available depending on the applicable standard, size and project requirement.
Large Diameter Weld Neck Flanges
Large diameter Weld Neck Flanges are commonly used where a welded flange connection is required.
The flange is designed to connect with the pipe through welding, with the flange geometry selected according to the specified standard and application.
Correct pipe outside diameter, wall thickness and flange specification should be confirmed before production.
Large Diameter Blind Flanges
Blind Flanges provide a closure for large-diameter piping systems.
They may be used for:
Pipeline ends
Equipment nozzles
Maintenance isolation
Future piping extensions
Pressure-containing closures
The blind flange must be selected according to the required NPS, class, material, facing and series.
ASME B16.47 Flange Facing
Large diameter flanges can be supplied with the specified facing arrangement according to the applicable standard and project requirement.
Common facing configurations include:
Raised Face (RF)
Flat Face (FF)
Ring Type Joint (RTJ)
The required facing should be confirmed before production because the face configuration affects the flange connection and gasket arrangement.
ASME B16.47 Flange Materials
Vandan Alloys supplies large diameter flange requirements in various materials, subject to the applicable specification.
Materials can include:
Carbon Steel
Stainless Steel
Alloy Steel
Duplex Stainless Steel
Super Duplex Stainless Steel
Nickel Alloys
Common customer requirements may include grades such as:
ASTM A105, ASTM A182 F304/F304L, F316/F316L, Duplex 2205 and Super Duplex 2507, along with other specified grades.
Material suitability must be confirmed against the applicable pressure-temperature requirements and project specification.
Large Diameter Flange Dimensions
Important dimensions can include:
Outside Diameter, Flange Thickness, Bore, Bolt Circle Diameter, Number of Bolt Holes, Bolt Hole Diameter, Facing Dimensions and Overall Flange Geometry.
Because Series A and Series B can have different dimensions, the series should always be clearly identified.
Series A vs Series B – Why It Matters
The most important point for buyers is that Series A and Series B are different dimensional configurations.
A flange with the same:
NPS + Class
may still require different dimensions depending on whether the project calls for Series A or Series B.
For replacement flanges, it is therefore recommended to check the existing flange marking, drawing or dimensional details before ordering.
Large Diameter Flange Inspection
Dimensional inspection is particularly important for large flanges.
Inspection can include:
Outside Diameter
Thickness
Bore
PCD
Bolt Hole Quantity
Bolt Hole Diameter
Facing Dimensions
RTJ Groove, where applicable
Overall Dimensional Requirements
Inspection criteria should follow the applicable standard, approved drawing and purchase specification.
Marking & Material Traceability
Large diameter flanges can be marked with relevant identification required by the applicable specification and purchase order.
Marking may include:
Manufacturer Identification, Material Grade, NPS, Pressure Class, Series, Standard and Heat Number, where required.
Material traceability is important for project documentation and quality control.
Documentation
Depending on the order requirement, documentation can include:
Material Test Certificate (MTC)
EN 10204 Type 3.1
Dimensional Inspection Report
Heat Treatment Documentation, where applicable
Other Agreed Quality Documents
Third-party inspection can also be arranged when required by the customer or project.
Applications of Large Diameter Flanges
ASME B16.47 large diameter flanges are used in applications such as:
Oil & Gas Pipelines
Refineries
Petrochemical Plants
Power Generation
Process Plants
Water Infrastructure
Large-Diameter Piping Systems
Industrial Equipment Connections
The correct flange specification depends on the engineering requirements of each project.
Large Diameter Flange Replacement
When replacing an existing large diameter flange, do not rely only on the nominal pipe size.
Provide as much information as possible, including:
NPS + Class + Series + Flange Type + Material + Facing + Existing Dimensions + Drawing, if available.
This helps avoid dimensional mismatch during installation.
Vandan Alloys – Large Diameter Flange Manufacturer & Exporter
Vandan Alloys manufactures and supplies industrial flanges from India for domestic and international customers.
We support requirements involving ASME B16.47 large diameter flanges, Series A and Series B configurations, Weld Neck Flanges and Blind Flanges in different materials and pressure classes.
Our focus is on accurate specification review, dimensional requirements, material traceability, quality documentation and export-ready packing.
Request a Large Diameter Flange Quotation
For an ASME B16.47 enquiry, please provide:
NPS | Flange Type | Series A/B | Pressure Class | Material Grade | Facing | Quantity | Drawing, if available | Delivery Location
Example:
NPS 36 WNRF – Series A – Class 300 – ASTM A105 – RF – 4 Nos
Our team can review the complete requirement and provide technical and commercial assistance.
Vandan Alloys
Manufacturer of All Types of Flanges
3/5, Sakar Bhavan, Ground Floor, 6th Khetwadi lane, SVP Road ,Mumbai – 400 004. India
TEL+91 022 6610 9925Mobile no: 09892882255 GSTIN: 27AUMPS2067F1ZB
Email: info@vandanalloys.com ; Web: www.vandanalloys.com
Please visit Our Flanges Division:www.vandanalloys.net
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ASME B16.47 large diameter flange guide covering NPS 26–60, Series A and Series B, pressure classes, materials, types and inspection.
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