ASTM A182 F53 Super Duplex Weld Neck Flange UNS S32750 for Petroleum Chemical Offshore

Super Duplex 2507 Flange ASTM A182 F53 / UNS 32750 Weld Neck Flange WNRF Flange

This weld neck flange is a single-piece forged component made from super duplex stainless steel grade UNS S32750, supplied to the ASTM A182 / ASME SA182 Grade F53 specification and machined with a raised face (RF) sealing surface, which is why the item is normally shortened to WNRF. The grade is also marketed as Duplex 2507, Alloy 2507, 1.4410 and X2CrNiMoN25-7-4, so buyers comparing quotations may see all of these names pointing at the same material.

The weld neck geometry is the other half of the value. The long tapered hub transfers pipe bending moment into the fitting gradually instead of concentrating it at a fillet, and the single butt weld can be fully radiographed, which is exactly what high-pressure and sour-service specifications demand. Because the material is stronger than 316L, wall thickness and bolt loads can often be reduced, cutting both weight and installed cost on offshore and topside structures.

*Typical service envelope: sizes 1/2" to 48", pressure classes 150# to 2500#, wall thicknesses Sch 5S to Sch XXS, sealing faces RF, FF or RTJ. Dimensions follow ASME B16.5 (and B16.47 for large diameters) unless an EN, JIS, DIN or project specification is nominated.

Chemical Composition of ASTM A182 F53 Super Duplex Steel Flange Duplex 2507 Weld Neck Flange 

Mechanical properties of ASTM A182 F53 Super Duplex Steel Flange Duplex 2507 Weld Neck Flange

Equivalent Grade and Alternative Grades

Packaging and Shipping

Flanges are supplied in plywood cases or on pallets, seaworthy packed for container or break bulk shipment. Machined faces are protected with plastic or wooden face discs, threads and grooves are capped, and each bundle carries a rust-preventive VCI lining for long sea transit.

1. Marking on flange: heat number, size, pressure class, type, standard and grade
2. Shipping marking on case: purchase order number, item description, quantity, net and gross weight, dimensions
3. Standard packing: plywood case or pallet, strapped and shrink wrapped; fumigation-free ISPM 15 compliant wood
4. Export port: Ningbo or Shanghai, other Chinese ports by arrangement
5. Commercial invoice and packing list supplied before vessel departure

Application

• Oil & Gas: Subsea manifolds, riser bases, wellhead Christmas trees, choke and kill lines, and topside process piping handling wet gas with CO2 and H2S. Material is normally ordered to NACE MR0175 / ISO 15156 for sour service and to API 6A or API 17D where a project specification applies.

• Chemical Processing: Heat exchanger shells and channels, reactor charge lines, and piping carrying chlorides, acetic acid, formic acid or dilute sulphuric acid where 316L and even 904L show inadequate pitting resistance.

• Seawater, Desalination and Marine: Reverse osmosis high-pressure trains, brine lines, seawater cooling systems, fire-fighting rings, and shipboard piping. The grade tolerates flowing seawater with residual chlorine far better than austenitic grades and is a common substitute where titanium is considered over-specified.

• Pulp, Paper and Mineral Processing: Bleaching plant piping handling chlorine dioxide, digester lines, and slurry handling where combined abrasion and chloride attack occur.

• Power and Flue Gas Desulphurisation: Absorber and slurry recirculation piping, and seawater-based FGD systems where chloride levels rule out duplex 2205.