Fluid, piping & valves
Special-alloy fittings and flanges
Pipe fittings, flanges, tube fittings and instrument valves in special alloys, including duplex 2205, super duplex, 6Mo austenitic steel and nickel alloys, for seawater, chloride, high-temperature and aggressive chemical service.
Overview
Where standard 304 and 316 stainless steels are not enough, special alloys extend the range. Duplex 2205 (UNS S31803/S32205) and super duplex grades (UNS S32750, S32760) combine strength with resistance to chloride stress corrosion. Nickel-chromium-molybdenum alloys such as C276 and nickel-copper alloys are used for strongly corrosive chemicals and seawater. Duplex products include seamless and welded pipe, butt-weld fittings from 1/2 in to 24 in NB, forged socket-weld and threaded fittings from 1/8 in to 4 in, and flanges in slip-on, weld-neck, blind, lap-joint, threaded, socket-weld, reducing and plate types. Alloy tube fittings, unions, needle valves, ball valves and manifolds are offered with NPT and BSP ends.
Selecting a special alloy
Alloy choice depends on the media, chloride level, temperature and pressure, and on the welding and fabrication involved. State the alloy by UNS number or ASTM grade where possible, and confirm the product form, size, pressure class and end connection.
Range overview
- Types and variants
- Duplex and Super Duplex Butt-Weld Fittings
- Duplex Forged Socket-Weld and Threaded Fittings
- Duplex Flanges
- Duplex Seamless and Welded Pipe
- Nickel-Alloy Tube Fittings and Unions
- C276 Needle Valves
- C276 Manifold Valves
- C276 Ball Valves
- Nickel-Copper Manifold Valves
- High-Alloy Forged Fittings
- Materials and grades
- Duplex 2205 (UNS S31803/S32205, W.Nr 1.4462)
- Super Duplex (UNS S32750, S32760)
- ASTM A182 F51, F53, F55, F60
- 254 SMO
- Hastelloy C276
- Inconel
- Monel 400
- Size range
- Butt-Weld: 1/2 in to 24 in NB
- Forged: 1/8 in to 4 in
- Flanges: 1/2 in to 24 in
- Alloy Valves and Fittings: 1/2 in to 2 in
- Pressure / temperature
- Forged fittings: 2000 lb, 3000 lb, 6000 lb, 9000 lb
- Flanges: Class 150, 300, 600, 900, 1500, 2500
- Flanges: PN6, PN10, PN16, PN25, PN40, PN64
- Schedules 10S, 40S, 80S, 160S, XXS
- Connections and interfaces
- Butt-Weld
- Socket-Weld
- Threaded
- Flanged RF/FF
- NPT
- BSP
- Standards referenced
- ASTM A815
- ASTM A182
- ASME B16.9
- ASME B16.28
- MSS SP-43
- ASME B16.5
- ASME B16.47 Series A and B
- ASME B16.48
- EN 1092
- BS 4504
- Features
- Wide Range of Alloy Product Forms
- Pipe, Fittings, Flanges and Valves in Matching Alloys
Exact specifications depend on the variant, material and size. Confirm ratings and certification against the datasheet or with our engineers before ordering.
Applications
- Seawater and Desalination
- Chemical Processing
- Oil and Gas Pipelines
- Heat Exchangers
- LNG
- Geothermal
Industries
- Chemical
- Oil and gas
- Marine
- Pulp and paper
- Food processing
- Pharmaceutical
- Power generation
Information that speeds up a quotation
Share what you know. Anything you are unsure of can be marked “not known” — our engineers will help confirm it.
- Nominal size
- Pressure class
- Material
- End connection
- Standard
- Temperature
- Media
- Drawing
- Certification
Need a datasheet?
Add this family to your enquiry list and mention the variant — we will send the relevant technical documents.
Piping and hydraulic connections
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Frequently asked questions
How do I choose between duplex, super duplex and nickel alloys?
Duplex 2205 is often a step up from 316 where chlorides or stress corrosion are a concern. Super duplex is considered for higher chloride levels, such as seawater. Nickel alloys are considered for strong acids and other severe chemical service. The final choice should be based on your media, temperature and the relevant design codes.
What documents can I request with special-alloy products?
You can request material test certificates showing chemical composition and mechanical properties, and, where your project needs them, positive material identification records, heat treatment records and dimensional reports. State the required documents in the enquiry so they can be confirmed at quotation stage.
Ready to specify special-alloy fittings and flanges?
Send the details you have — quantities, sizes, drawings or a part number. Unknowns are fine.