Weld Neck
Weld Neck Flange
Circumferentially welded at the hub. The tapered neck relieves stress concentration, making it the standard for severe service.
- Standard ASME B16.5 / B16.47
- Size 1/2" – 80"
- Class 150 – 2500
- Face RF, FF, RTJ
Catalogue
14 Flange Types
Filter by connection type. Every product is available in carbon, stainless, duplex and nickel alloys.
Weld Neck
Slip On
Slip On Flange
Slides over the pipe and is fillet welded both inside and outside. Cheaper to install and easier to align than a weld neck.
- Standard ASME B16.5 / EN 1092-1
- Size 1/2" – 60"
- Class 150 – 1500
- Face RF, FF
Blind
Blind Flange
A solid disc used to close off a pipe, valve or vessel nozzle. Allows future access while isolating the line completely.
- Standard ASME B16.5 / B16.47
- Size 1/2" – 80"
- Class 150 – 2500
- Face RF, FF, RTJ
Socket Weld
Socket Weld Flange
Pipe sits in a counter-bored socket with a single fillet weld outside. Smooth bore gives good flow and fatigue resistance.
- Standard ASME B16.5
- Size 1/2" – 4"
- Class 300 – 2500
- Face RF, RTJ
Threaded
Threaded Flange
Internal NPT or BSP thread screws onto the pipe — no welding needed. Used where hot work is not permitted.
- Standard ASME B16.5 / B16.36
- Size 1/2" – 24"
- Class 150 – 2500
- Thread NPT / BSP
Lap Joint
Lap Joint Flange
Loose backing flange over a stub end. Easy bolt-hole alignment and the flange can be reused — ideal for expensive alloys.
- Standard ASME B16.5
- Size 1/2" – 48"
- Class 150 – 900
- Face RF, FF
Orifice
Orifice Flange
Supplied in pairs with raised-face or RTJ finish and integral 1/8" NPT pressure tappings for flow measurement.
- Standard ASME B16.36
- Size 1/2" – 24"
- Class 150 – 2500
- Type WN, SO, Threading
Long Weld Neck
Long Weld Neck Flange
Extended straight neck replaces a short pipe spool. Standard in vessel and column nozzle connections.
- Standard ASME B16.5 / MSS SP-44
- Size 1" – 36"
- Class 150 – 2500
- Neck 150 – 600 mm custom
Spectacle Blind
Spectacle Blind Flange
A paddle-and-spacer pair that visibly shows whether a line is open or isolated. Supplied with studs, nuts and gaskets.
- Standard MSS SP-75
- Size 1" – 48"
- Class 150 – 1500
- Face RF, RTJ
Expander
Expander Flange
Increases the bore by one or two sizes in a single component, saving a separate reducer and an extra weld.
- Standard ASME B16.5 / custom
- Size 2" – 24"
- Class 150 – 900
- Type WN, SO
Reducing
Reducing Flange
Outside diameter matches the larger line while the bore steps down to the smaller pipe. Compact and leak-proof.
- Standard ASME B16.5 / custom
- Size 1/2" – 24"
- Class 150 – 900
- Type WN, SO, Blind
Groove & Tongue
Groove & Tongue Flange
Mating faces self-align and retain the gasket, giving a reliable seal in vacuum and low-pressure-drop service.
- Standard ASME B16.5 / EN 1092-1
- Size 1/2" – 36"
- Class 150 – 900
- Face TG, M&F
Plate
Plate Flange
Flat plate flange to DIN, BS 10 and SABS 1123 — widely used on water, structural and low-pressure pipework.
- Standard DIN 2631–2635 / BS 10
- Size DN15 – DN2400
- Rating PN6 – PN40 / Table D–H
- Face FF, RF
Anchor
Anchor Flange
Bolted to a structural member to restrain thermal movement in buried or above-ground pipelines and cross-country lines.
- Standard AWWA C207 / custom
- Size 4" – 60"
- Class 150 – 900
- Design To client drawing
Need a non-standard flange? We machine to customer drawings — send us your specification.
Metallurgy
Materials & Grades
All grades sourced from primary mills with full heat-number traceability.
| Family | Common Grades | Typical Application |
|---|---|---|
| Carbon Steel | ASTM A105 / A105N, A350 LF2, A694 F52–F65 | Oil & gas lines, refineries, low-temperature service |
| Stainless Steel | ASTM A182 F304/L, F316/L, F321, F347 | Corrosive process, food, pharma, marine |
| Duplex / Super Duplex | F51 (2205), F53 (2507), F55 | Offshore, chloride-rich and sour service |
| Alloy Steel | ASTM A182 F5, F9, F11, F22, F91 | High-temperature steam and power plant piping |
| Nickel Alloys | Inconel 600/625/800, Monel 400, Hastelloy C276/B2, Incoloy 825 | Severe corrosion, chemical processing, high heat |
| Copper Nickel | CuNi 90/10, CuNi 70/30 | Seawater cooling, shipboard pipework |
| Low Temperature | A350 LF2 / LF3 (impact tested to −46 °C) | LNG, cryogenic and refrigeration service |
| Titanium | Grade 2, Grade 5 | Chloride and oxidising environments |
Compliance
Standards We Manufacture To
We work to both imperial and metric dimensional standards, and will produce to a customer drawing where no standard applies.
ASME B16.5
ASME B16.47 A/B
ASME B16.36
MSS SP-44
MSS SP-75
EN 1092-1
DIN 2631–2635
BS 10 Table D–H
JIS 5K / 10K / 20K
SABS 1123
AWWA C207
GOST 12820/12821
Pressure-Temperature
Class Rating Reference
| Class | Max Pressure (bar) | Common Use |
|---|---|---|
| 150# | 19.2 @ 20 °C | Utilities, water, low-pressure process |
| 300# | 51.0 @ 20 °C | General oil & gas, steam |
| 600# | 102.0 @ 20 °C | Refinery, high-pressure process |
| 900# | 153.0 @ 20 °C | Wellheads, severe service |
| 1500# | 255.0 @ 20 °C | Subsea, high-pressure gas |
| 2500# | 425.0 @ 20 °C | Critical pressure containment |
Values are indicative for carbon steel at ambient temperature. Ratings fall as temperature rises — refer to ASME B16.5 pressure-temperature tables for your specific material.
Common Questions
Before You Order
Flange type, nominal size, pressure class, material grade, facing finish (RF / FF / RTJ) and quantity. A datasheet, line list or drawing works just as well — send whatever you have and our desk will fill in the gaps with you.
Stocked carbon steel sizes ship in 5–7 working days. Made-to-order carbon and stainless flanges take 15–20 working days; duplex and nickel alloys 25–35 working days depending on raw material availability.
Yes. Our works is regularly audited by SGS, BV, TÜV, LR, DNV and ABS. You may also nominate your own inspector; we will arrange the inspection call and hold points at no extra charge.
Every dispatch includes EN 10204 3.1 certificates as standard, with 3.2 certificates available where third-party witnessed. Heat numbers are stamped on the flange and matched to the certificate.
There is no minimum for stocked sizes. For made-to-order and special grades, a single piece can be produced, though pricing is more favourable from about 10 pieces upward.
Yes — custom and proprietary designs are a large part of our work. Send a PDF or DWG and we will confirm feasibility, tooling and lead time within two working days.
Send Us Your Line List
Upload a datasheet or drawing and receive a priced offer the same working day.