Why Buyers Trust Ganpat Industrial For Alloy Steel F91 Flanges?

Since 1997

Three decades supplying alloy and stainless piping material out of Mumbai

Forging Manufacturer

In-house forging for flanges, fasteners and bars, plus stocked pipe and plate

ISO 9001:2015

Certified quality system, audited every year, alongside ISO 14001:2015

PED & Petrofac Approved

Cleared for European pressure equipment work and Petrofac vendor lists

OHSAS 18001:2007

Full mill test certificate and heat-traceable documentation on every lot

Alloy Steel F91 Flanges At A Glance

1Material Basis: Modified 9Cr-1Mo-V Martensitic Alloy Steel • UNS K90901 • Werkstoff 1.4903
2Governing Standard: ASTM A182 / ASME SA182 Grade F91 • Dimensions To ASME B16.5 & B16.47
3Size Range: ½ Inch To 24 Inch Under ASME B16.5, 26 Inch To 60 Inch Under B16.47
4Pressure Class: Class 150# To 2500# Rating, Raised Face & Ring Type Joint
5Equivalents: DIN/EN 1.4903 • ASTM A335 P91 (Pipe) • A234 WP91 (Fittings)
6Forms Supplied: Weld Neck, Slip On, Blind, Socket Weld, Threaded, Lap Joint & Orifice

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Ganpat Industrial Corporation has supplied Indian and export piping buyers since 1997. As an Alloy Steel F91 Flanges Supplier in India, we forge and stock flanges. We offer ASTM A182 Grade F91 Weld Neck, Blind, and Slip On flanges. We supply these flanges in sizes from ½ inch through 24 inches. Larger flange diameters are sourced according to the ASME B16.47 standard. Grade 91 carries controlled vanadium, niobium, and nitrogen additions. These additions lift creep strength well beyond plain 9Cr-1Mo. It is the standard choice for supercritical boiler headers. It also supports main steam lines and hot reheat piping running up to 650°C. Every flange is normalized and tempered to the ASTM A182 heat treatment schedule. We machine each flange accurately to the required facing. Every despatch includes an EN 10204 3.1 mill test certificate. We regularly ship this grade to power plant EPC contractors. Key domestic markets include Gujarat, Chhattisgarh, and Tamil Nadu. We also export to the Middle East and Southeast Asia.

Mumbai · High-Temperature 9Cr-1Mo-V Flange Stockist & Exporter

Alloy Steel F91 Flanges Manufacturer in India – Forging, Facing & Certification Snapshot

Ganpat Industrial is a driven-pricing Alloy Steel F91 Flanges Supplier in India. We forge SA182 F91 Weld Neck, Blind and Slip On flanges from ½ inch to 24 inch, rated Class 150# to 2500#, for boiler and power piping running up to 650°C.

✓ISO 9001:2015
✓ISO 14001:2015
✓OHSAS 18001:2007
✓PED Certified
✓Petrofac Approved

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View Specification

UNS Designation

K90901

Werkstoff 1.4903, formerly cross-referenced T91

Chromium-Moly-V

9Cr-1Mo-V

Modified with Nb, V & controlled nitrogen

Dimensional Standard

ASME B16.5

ASME B16.47 Series A/B above 24 inch

Pressure Class

150# – 2500#

Class 2500# limited to 12 inch NB

Explore ASTM A182 Grade F91 Blind Flanges Supplier in India With Class 150# to 2500# Rating at Best Price

Specification Of Alloy Steel F91 Flanges

Every Alloy Steel F91 Flanges order is checked against this specification sheet before dispatch.

Material Basis

Modified 9Cr-1Mo-V Martensitic Steel
UNS K90901
Werkstoff 1.4903
Normalized & Tempered

Governing Flange Standards

ASTM A182 / ASME SA182 Grade F91
ASME B16.5 (½″ to 24″)
ASME B16.47 Series A/B (26″ to 60″)
Facing To ASME B16.5 Table 8

Flange Size & Class Range

½ Inch To 60 Inch NB
Class 150# To 2500#
Class 2500# Up To 12 Inch Only
DN15 To DN1500

Flange Types Supplied

Weld Neck, Slip On & Blind
Socket Weld & Threaded
Lap Joint & Orifice
Spectacle Blind & Plate Flange

Delivery Condition

Normalized & Tempered
Normalize 1040-1080°C, Air Cool
Temper 730-800°C
Bevelled Ends To ASME B16.25

Production Route

Hot Forged From Billet/Bar
Rough Machined To Near Shape
Normalize & Temper Heat Treatment
Finish Machined & Faced

Testing Offered

PMI Spectro Analysis
Ultrasonic Test On Forgings
Hardness & Tensile Test
Third Party Inspection

Matching Products

ASTM A335 P91 Seamless Pipe
ASTM A234 WP91 Buttweld Fittings
A193 B16 / A194 Gr 7 Bolting
SA387 Grade 91 Plate

Packing

Individually Capped Bores
Wooden Crates, Fumigated For Export
Grade & Heat Number Tags
VCI Wrap For Sea Freight

SA182 F91 Weld Neck Flange Dimensions Chart

Outside diameter by nominal size across the seven ASME B16.5 pressure classes.

Flange Outside Diameter (mm), ASME B16.5
NPS	Class 150	Class 300	Class 600	Class 900	Class 1500	Class 2500
½″	88.9	95.3	95.3	120.7	120.7	133.4
1″	108.0	123.8	123.8	149.2	149.2	158.8
2″	152.4	165.1	165.1	215.9	215.9	235.0
4″	228.6	254.0	273.1	292.1	311.2	355.6
6″	279.4	317.5	355.6	381.0	393.7	482.6
8″	342.9	381.0	419.1	469.9	482.6	552.5
12″	482.6	520.7	558.8	609.6	673.1	762.0

ASTM A182 F91 Flanges Sizes

Sizes above NPS 24 move from ASME B16.5 to the ASME B16.47 large-diameter standard.

Size Range

26″ – 60″ NB

Covered under ASME B16.47, not B16.5

Series A

MSS SP-44 Basis

Heavier drilling, common on power plant lines

Series B

API 605 Basis

Lighter drilling, confirm interchangeability first

Series Compatibility

Not Interchangeable

Series A and B bolt patterns differ, always confirm

Types Of Alloy Steel F91 Flanges We Supply

A dependable Alloy Steel F91 Flanges stockist forges and holds every common facing and hub type.

SA182 F91 Weld Neck Flange

WN / RF

Alloy Steel F91 Blind Flanges

Blind

Alloy Steel F91 Slip On Flange

SA182 F91 Type 1 Socket Weld Flanges

SW Type 1

Alloy Steel A182 F91 Lap Joint Flanges

Lap Joint

SA182 F91 Type 2 Orifice Flanges

Orifice

SA182 Gr F91 Plate Flange

Plate

Alloy Steel F91 Pipe Flanges

Threaded

Need ASTM A182 F91 Flanges Fast?Mail the size list with facing and rating, we quote inside 24 hours, large diameters included.

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Buy SA182 F91 Cl1/Cl3 Threaded & Socket Weld Flanges as per ANSI/ASME B16.5 & BS4504 Standards for Boiler, Power & Petrochemical Piping

Alloy Steel F91 Pipe Flanges Chemical Composition

Heat analysis held against ASTM A182 Table 1 limits for Grade F91.

IronFe

Balance

ChromiumCr

8.00 – 9.50%

MolybdenumMo

0.85 – 1.05%

CarbonC

0.08 – 0.12%

ManganeseMn

0.30 – 0.60%

SiliconSi

0.20 – 0.50%

VanadiumV

0.18 – 0.25%

NiobiumNb (Cb)

0.06 – 0.10%

NitrogenN

0.030 – 0.070%

NickelNi

0.40% max

PhosphorusP

0.020% max

SulphurS

0.010% max

AluminiumAl

0.020% max

SA 182 Grade F91 Weld Neck Flange Mechanical Properties

Minimum Values, Normalized & Tempered Condition

Inspectors check these figures against certificates for A182 F91 Type 1 Socket Weld Flanges.

Tensile Strength

620 MPa Min

90 ksi min, per ASTM A182

Yield Strength (0.2%)

415 MPa Min

60 ksi min

Elongation

20% Min

In 2 in. [50 mm] gauge length

Reduction Of Area

40% Min

Minimum per ASTM A182 Table 2

Brinell Hardness

190 – 248 HBW

Outside this band signals faulty heat treatment

Max Service Temperature

Up To 650°C

Allowable stress governed by ASME Section II Part D above 500°C

Structure

Tempered Martensite

Ferromagnetic, body-centred cubic lattice

Impact Testing

Charpy On Request

Notch toughness confirmed for low-temperature clauses

A182 F91 Type 2 Blind Flanges Heat Treatment Cycle

A trusted Alloy Steel F91 Flanges Manufacturer in India rejects annealing as a substitute.

Forging To Shape

Billet or bar hot forged into flange blank at works

Normalizing

Heated to 1040-1080°C, held, then air cooled

Tempering

Reheated to 730-800°C to relieve martensite hardness

Hardness Check

Brinell confirmed inside the 190-248 HBW window

Machining & Dispatch

Faced, drilled and shipped with EN 10204 3.1 certificate

Alloy Steel F91 Slip On Flange Equivalent Grades

One Chemistry, Several Product Forms

Alloy Steel F91 Flanges read the same 9Cr-1Mo-V chemistry across every governing standard.

ASTM / UNS

ASTM A182 Grade F91
ASME SA182 Grade F91
UNS K90901

DIN / EN / Werkstoff

Werkstoff Nr. 1.4903
EN X10CrMoVNb9-1
Same UNS K90901 Basis

Related ASTM Product Forms

ASTM A335 Grade P91 (Pipe)
ASTM A213 Grade T91 (Tube)
ASTM A234 Grade WP91 (Fittings)

Plate & Casting Forms

ASTM A387 Grade 91 (Plate)
ASTM A217 Grade C12A (Casting)
Same 9Cr-1Mo-V Basis

Nearby ASTM A182 Grades

ASTM A182 F9 (Plain 9Cr-1Mo)
ASTM A182 F92 (W-bearing, Higher Creep)
ASTM A182 F22 (2.25Cr-1Mo)

Indian Market Note

No Single-Number IS Equivalent
Ordered Directly As F91 / Grade 91
Compared By Chemistry Basis

Weekly Delivery Of Alloy Steel F91 Flanges In Below Locations

Export To	Continent	Port	Shipping Time
UAE	Middle East	Jebel Ali Port	12 Days
Saudi Arabia	Middle East	Dammam Port	14 Days
Indonesia	Southeast Asia	Tanjung Priok Port	18 Days

Alloy Steel F91 vs F22 Flanges

Buyers moving up from lower Chrome-Moly grades usually ask this before confirming an order.

ASTM A182 F22 Flanges

1-1.5Cr or 2.25Cr, plain Mo, no V/Nb
Lower allowable stress above 550°C
Simple anneal or normalize-and-temper
Lower material cost than F91

Alloy Steel F91 Flanges

9Cr-1Mo with V, Nb and controlled N
Roughly 30% higher allowable stress near 600°C
Mandatory normalize-and-temper cycle
Preferred for supercritical & USC boiler lines

SA182 Gr F91 Plate Flange Facing Options

Facing finish and raised face height are set by class per ASME B16.5.

Class 150 & 300 RF Height

1.6 mm

Standard raised face above the gasket face

Class 400 – 2500 RF Height

6.4 mm

Taller raised face at higher classes

Ring Type Joint

RTJ Groove

Common on Class 900 and above for boiler headers

Surface Finish

125-250 AARH

Serrated concentric or spiral finish, confirmed on order

F91 Spectacle Blind Flange Forging & Machining Process

From Billet To Certified Flange

How UNS K90901 stock becomes a finished, traceable Alloy Steel F91 Pipe Flanges piece at our works.

Billet Selection

Heat-certified F91 bar cut to forging weight

Hot Forging

Upset and ring-rolled into the flange blank

Normalize & Temper

Heat treated per the ASTM A182 F91 cycle

Machining & Facing

Bore, bolt circle and facing cut to drawing

Inspection & Dispatch

PMI, hardness and dimensions cleared before crating

Alloy Steel A182 F91 Lap Joint Flanges Application Industries

Grade 91 flanges suit high-temperature circuits across a focused industrial spread.

Supercritical & USC Boilers

Main Steam & Hot Reheat Lines

Petrochemical & Refinery Piping

Heat Recovery Steam Generators

Combined-Cycle Power Plants

High-Pressure Header Assemblies

Hydrogen & Process Gas Lines

Nuclear & Fossil Boiler Retrofits

SA182 F91 Flange HSN Code & GST In India

Consult an Alloy Steel F91 Flanges Supplier in India before raising a purchase order.

HSN Heading

7307

Tube or pipe fittings of iron or steel

Sub-heading

7307 91 90

Flanges, other alloy/carbon steel

GST Rate

18%

Standard rate on iron/steel pipe fittings

Export Benefit

LUT / Zero-Rated

Confirm current scheme with your CA before shipment

Alloy Steel F91 Flanges Price In India

Driven Pricing, Not A Flat Rate Card

Chrome-moly billet and forging cost move week to week, so our F91 pricing follows current input rates.

•Flange Type & Facing

•Size & Pressure Class

•Normalize & Temper Cycle

•PMI, RT & TPI Called Out

•HSN 7307 • GST 18%

•Quantity & Delivery Port

Today’s Alloy Steel F91 Flanges Rate

Send a size and class-wise list for per-piece pricing. Get it inside 24 hours, HSN and GST already worked out.

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Alloy Steel F91 Flanges Monthly Delivery In Below Countries

Export To	Continent	Port	Shipping Time
South Africa	Africa	Port of Durban	26 Days
Netherlands	Europe	Port of Rotterdam	28 Days

Stock, MOQ & Dispatch Timeline

From Enquiry To Gate Pass

The real clock on an Alloy Steel F91 Flanges order, not a marketing promise.

Day 0 – Enquiry

Mail size, class and facing to our Mumbai desk

Day 1 – Driven Quote

Per-piece rate against current input cost, GST included

Day 2 – Inspection

Chemistry, hardness and dimensions cleared, TPI called if needed

Day 3 – Dispatch

Stock sizes leave with LR copy and full document set

Stock Range

½ – 12 Inch

Class 150 to 900 held in Mumbai

Minimum Order

25 Kg

Per size, trial lots considered

Large Size Lead Time

20 – 30 Days

Above 12 inch or Class 1500/2500, forged to order

Export Transit

Nhava Sheva

Air or sea, FOB CFR CIF DDP quoted

SA182 F91 Type 2 Orifice Flanges Documentations

As an Alloy Steel F91 Flanges Supplier in India, our paperwork matches physical flanges.

Mill Test Certificate

Chemical and mechanical results per EN 10204 3.1

Standard

Third Party Inspection Report

SGS, BV, TUV or Lloyd’s, arranged on request

On Request

Ultrasonic Test Record

Internal soundness check on forgings per ASTM A388

Standard

Heat Treatment Chart

Normalize and temper time-temperature record, per lot

Standard

Certificate Of Origin

Chamber-attested, needed for most export shipments

Export

Packing List & Invoice

Heat-number traceable listing for every carton or crate

Standard

A182 F91 Type 1 Socket Weld Flange Testings

A serious Alloy Steel F91 Flanges producer tests every forged batch before dispatch.

Chemical / PMI Analysis

Spectro reading against UNS K90901 composition limits

Hardness Test

Brinell readings recorded lot-wise, checked against 190-248 HBW

Tensile & Yield Test

Tensile, yield and elongation tested per ASTM A182

Ultrasonic Testing

Internal soundness confirmed per ASTM A388 on forgings

Dimensional Inspection

OD, bolt circle, facing and bore checked against ASME B16.5

Heat Treatment Verification

Time-temperature chart matched against ASTM A182 Table 3

Alloy Steel F91 Flanges Frequently Asked Questions

What is the material grade F91?

Modified 9Cr-1Mo-V martensitic alloy steel, ASTM A182, UNS K90901, for boiler and steam piping.

What is the difference between F9 and F91?

F91 adds vanadium, niobium and nitrogen, giving about 30% higher allowable stress.

Are F91 and P91 the same material?

Same 9Cr-1Mo-V chemistry; F91 is for flanges/fittings, P91 is for pipe.

Can F91 flanges be supplied in Class 2500#?

Yes, but only up to NPS 12 per ASME B16.5.

What is the HSN code for Alloy Steel F91 Flanges?

HSN 7307, taxed at 18% GST in India.

We Collaborate With Traders in the Following Locations

Kuwait	Qatar	Bahrain	Muscat	Dubai	Sharjah
Jamnagar	Vadodara	Chennai	Vizag	Kandla	Mundra
Saudi Arabia	Riyadh	Dammam	Al-Khobar	Jubail	Yanbu
Indonesia	Malaysia	Vietnam	Thailand	Philippines	Bangladesh
South Africa	Nigeria	Egypt	Kenya	Tanzania	Algeria