Product Category

PipeFlanges

A complete range of pipe flanges in all types, pressure classes and materials — manufactured to ANSI/ASME B16.5, DIN, EN and IS standards for oil & gas, petrochemical, power and industrial piping systems worldwide.

600+ SKUs

ISO 9001:2015

ANSI · ASME · DIN · EN

½” to 48″ / DN15–DN1200

CS · SS · Alloy · Duplex

Class 150 to 2500

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Flange Types Range

Every flange type, every pressure class, every material — for all piping system applications from low-pressure utility to high-pressure oil & gas.

Standard Flange Types

12+ Types

Special & Isolation Types

8+ Types

Pressure Ratings

ANSI Flange Pressure Classes

ANSI/ASME B16.5 defines 7 pressure classes. Select the correct class based on your system design pressure and operating temperature.

150

Class 150

~285 PSI @ 100°F · A105

General purpose — water, steam, gas and oil for low to medium pressure utility piping. Most common class worldwide.

300

Class 300

~740 PSI @ 100°F · A105

Moderate to high pressure — process piping, steam systems and industrial applications requiring more than Class 150.

600

Class 600

~1480 PSI @ 100°F · A105

High-pressure oil & gas, petrochemical and refinery lines. Standard in upstream oil & gas and chemical plants.

900

Class 900

~2220 PSI @ 100°F · A105

Very high pressure piping — power generation, high-pressure steam systems and critical process lines.

1500

Class 1500

~3705 PSI @ 100°F · A105

Extreme pressure — wellhead systems, high-pressure injection lines and critical process requirements.

2500

Class 2500

~6170 PSI @ 100°F · A105

Highest ANSI class — ultra-high pressure systems, test equipment and special critical pressure vessel connections.

Technical Reference

Flange Specifications & Standards

Quick reference for flange types, applicable standards, materials and size ranges.

Flange Type	Standard	Material Grade	Size Range	Pressure Class	Facing
Slip-On Flange	ANSI B16.5DIN 2573	A105 · A182 F304/316 · F11 · F22	½” – 24″	Class 150–600	RF · FF · RTJ
Weld Neck Flange	ANSI B16.5B16.47	A105 · A182 F304/316/L · F51 · F53	½” – 48″	Class 150–2500	RF · FF · RTJ · LJ
Blind Flange	ANSI B16.5DIN 2527	A105 · A182 F304/316 · F11 · F22	½” – 48″	Class 150–2500	RF · FF · RTJ
Socket Weld Flange	ANSI B16.5	A105 · A182 F304/316	½” – 3″	Class 150–2500	RF · FF · RTJ
Threaded Flange	ANSI B16.5	A105 · A182 F304/316	½” – 4″	Class 150–2500	RF · FF
Lap Joint Flange	ANSI B16.5	A105 · A182 F304/316	½” – 24″	Class 150–600	LJ Face
Orifice Flange	ANSI B16.36	A105 · A182 F316	1″ – 16″	Class 300–2500	RF · RTJ
Spectacle Blind	ASME B16.48API 590	A516 Gr.70 · A240 Gr.304/316	½” – 24″	Class 150–2500	RF · RTJ
EN 1092 Flange	EN 1092-1DIN 2501	P250GH · 1.4301 · 1.4404	DN15 – DN1200	PN6 to PN100	RF · FF · TG · MF
Long Weld Neck	ANSI B16.5	A105 · A182 F304/316 · F11	½” – 24″	Class 150–2500	RF · RTJ

Materials

Flange Materials & Grades

We manufacture flanges in a wide range of materials — from standard carbon steel to exotic alloys for high-temperature and corrosive environments.

Most Common

Carbon Steel

Standard carbon steel flanges for general industrial piping — cost-effective, strong and available in all flange types and all pressure classes.

ASTM A105A181 Gr.60/70A516 Gr.70IS 2062

Corrosion Resistant

Stainless Steel

For corrosive service — chemical processing, food & beverage, marine and pharmaceutical piping. Available in all austenitic and duplex grades.

A182 F304A182 F316A182 F316LF310 · F321

High Temperature

Alloy Steel

Chrome-molybdenum alloy flanges for high-temperature and high-pressure service — power generation, refineries and petrochemical plants above 400°C.

A182 F11A182 F22A182 F91F5 · F9

Offshore Grade

Duplex & Super Duplex

Superior strength and chloride corrosion resistance for offshore, subsea, desalination and aggressive chemical environments.

A182 F51 — Duplex 2205A182 F53 — S.Duplex 2507F55 · F60

Exotic Alloys

Inconel & Hastelloy

Nickel-based superalloy flanges for extreme temperature and corrosion — gas turbines, aerospace and chemical reactors beyond standard grade capability.

Inconel 625Inconel 718Hastelloy C-276Monel 400

Flange Facings

Facing Types

Flange facing determines the sealing surface and gasket type. We supply all standard facing configurations from flat face to ring type joint for high-pressure service.

Raised Face (RF)Flat Face (FF)Ring Type Joint (RTJ)Tongue & GrooveMale & Female

Product Details

Know Your Flange

Click any flange type to see full specifications, standards, typical applications and selection guide.

Slip-On Flange — When & How to Use

ANSI B16.5 · DIN 2573 · Most economical welded flange type

How It Works

The pipe slides through the flange bore and is welded both inside (fillet weld) and outside. This double weld provides strength but the internal weld can cause turbulence. Easier to align than weld neck but weaker — not recommended for high-pressure or cyclic service.

Best For

Low to medium pressure utility lines · Water, steam, gas & oil Class 150–300 · Non-critical process lines where weld neck is over-specified

Key Specifications

ANSI B16.5 · DIN 2573/2576 Class 150 · 300 · 600 Size: ½” – 24″ (DN15–DN600) A105 · A182 F304/316 · F11 RF · FF · RTJ facing 2 fillet welds required

Weld Neck Flange — The Premium Choice

ANSI B16.5 · B16.47 · For High-Pressure & Critical Service

How It Works

The long tapered hub is butt-welded to the pipe — creating a smooth bore transition that minimises turbulence and stress concentration. The strongest and most reliable flange type. Preferred for high-pressure, high-temperature and cyclic service where joint integrity is critical.

Best For

Oil & gas process lines · High-pressure steam · Refinery & petrochemical piping · All critical service above Class 300 · Any application where reliability is paramount

Key Specifications

ANSI B16.5 — ½” to 24″ ANSI B16.47 — 26″ to 48″ Class 150 to 2500 A105 · A182 F304/316/L A182 F11 · F22 · F91 F51 Duplex · F53 S.Duplex RF · FF · RTJ facing

Blind Flange — Closing Off Pipeline Ends

ANSI B16.5 · Used to blank off pipe ends or vessel nozzles

How It Works

A solid disc with no bore — used to close off a flanged end of a pipe, valve, pressure vessel or equipment nozzle. Can be unbolted to provide access or to add future connections. Subject to high bending stress at high pressure so thickness must be carefully calculated.

Best For

Pipe end closure · Vessel nozzle blanking · Isolation during maintenance · Future tie-in points · Pressure testing line ends

Key Specifications

ANSI B16.5 — All Classes DIN 2527 Size: ½” – 48″ A105 · A182 F304/316 A516 Gr.70 (plate material) RF · FF · RTJ facing

Socket Weld & Threaded Flanges

Small Bore · ANSI B16.5 · Class 150 to 2500

How They Work

Socket weld: the pipe inserts into the flange socket and is joined by a single fillet weld — cleaner bore than slip-on. Threaded: the flange screws directly onto a threaded pipe end with no welding required, making it ideal for hazardous or non-weldable locations.

Best For

SW: small bore high-pressure · Chemical injection · Instrument connections. Threaded: hazardous areas · Non-weldable materials · Remote field connections

Key Specifications

ANSI B16.5 — Both Types SW Size: ½” – 3″ Threaded: ½” – 4″ Class 150 to 2500 A105 · A182 F304/316 NPT / BSP Thread available

Spectacle Blinds & Paddle Spacers

ASME B16.48 · API 590 · Line Isolation & Spading

How They Work

A spectacle blind (figure-8 blank) has a solid disc and a ring connected by a solid bar. The flange is unbolted, rotated so either the blind or open ring is in the flow path, then re-bolted. Provides positive isolation — visible from outside. The paddle spacer is only the open ring half.

Best For

Process isolation during maintenance · Safety-critical line spading · Positive identification of isolated lines · Refineries & chemical plants requiring frequent isolation

Key Specifications

ASME B16.48 — Primary Std API 590 — Alternative Class 150 to 2500 Size: ½” – 24″ A516 Gr.70 · A240 Gr.304/316 Paddle Spacer — Open Ring Only

Why RR Hydraulic

Your Complete Flange Supplier

From Class 150 slip-on to Class 2500 weld neck in exotic alloys — we manufacture and supply the full flange range with NACE and ISO documentation.

All ANSI Classes — Class 150 to 2500 in all flange types, from stock and to order
½” to 48″ Available — Small bore instrument flanges to large diameter pipeline flanges
Exotic Material Grades — Duplex, Super Duplex, Inconel, Hastelloy, Monel and Titanium flanges available
Full MTR Documentation — PMI tested, heat-treated and dimensionally inspected with NACE MR0175 compliance
EPC Project Experience — Complete flange BOM supply for major oil & gas and petrochemical projects worldwide