ASTM A182 F55 Slip On Flanges — Super Duplex Zeron 100 Manufacturer
Tesco Steel & Engineering forges ASTM A182 F55 slip on flanges — super duplex Zeron 100 (UNS S32760), the 25Cr super duplex reinforced with deliberate copper and tungsten and the only common flange grade whose specification guarantees PREN ≥ 40 on every heat — to ASME B16.5 Class 150–2500 from ½″ to 24″ NB, larger patterns to order. The North Sea heritage grade of severe seawater, firewater and sour injection duty, supplied solution annealed, faced SORF (flat face or RTJ where specified), with sister grade F53 (S32750) and the F51/F60 duplex family from the same forge. NACE MR0175 supply on request; every lot with EN 10204 3.1/3.2 MTC. ISO 9001:2015, made in Mumbai, India — exported to 50+ countries.
ASTM A182 F55 · SA182 · S32760Zeron 100 · 1.4501 · PREN ≥ 40 GuaranteedCu 0.5–1.0% + W 0.5–1.0%ASME B16.5 Class 150–2500750 MPa TS / 550 MPa YS minNACE MR0175 / ISO 15156EN 10204 3.1 / 3.2 · ISO 9001:2015
ASTM A182 F55 Super Duplex Slip On Flange — Raised Face (SORF)
What is an ASTM A182 F55 Slip On Flange?
F55 = Zeron 100, the Cu+W super duplex.ASTM A182 F55 (UNS S32760) pairs the 25Cr-7Ni super duplex base with copper (reducing acids) and tungsten (crevice corrosion), and uniquely writes PREN ≥ 40 into the specification itself — guaranteed on every heat. Strength: 750/550 MPa, about triple the yield of 316L. As a slip-on, it installs with two fillet welds under tight super duplex heat-input control — no preheat, no PWHT. The North Sea's seawater and firewater standard.
Also searched as: Zeron 100 flange, S32760 slip on flange, super duplex slip on flange, F55 SORF flange, SA182 F55 slip on flange, 1.4501 slip on flange — all refer to the product on this page.
Super duplex — hot seawater, firewater, harshest offshore
A182 F55 / Zeron 100 (this page)
S32760
≥40 (guaranteed)
Super duplex with Cu+W — severe seawater & sour duty
PREN for tungsten-bearing grades = %Cr + 3.3×(%Mo + 0.5×%W) + 16×%N — and S32760 is the family's only member whose specification mandates the 40 threshold on every heat rather than merely implying it by composition.
ASTM A182 F55 (UNS S32760) Chemical Composition
C
Mn
Si
P
S
Cr
Ni
Mo
N
Cu
W
0.030 max
1.00 max
1.00 max
0.030 max
0.010 max
24.0-26.0
6.0-8.0
3.0-4.0
0.20-0.30
0.50-1.00
0.50-1.00
Values in weight % per ASTM A182 for UNS S32760. The copper and tungsten are deliberate ranged additions, not residual caps — they are what distinguish Zeron 100 from 2507 — and the specification additionally requires PREN ≥ 40 calculated with the tungsten term on every heat.
ASTM A182 F55 Mechanical Properties
Tensile Strength, MPa (ksi)
Yield Strength, Min, MPa (ksi)
Elongation % min (2")
750 (109) min
550 (80) min
25
Roughly triple the yield of 316L with the full 25% elongation of a solution-annealed duplex. Hardness is verified against the standard — and against the NACE MR0175 limits for sour lots. Values are demonstrated per heat on the EN 10204 certificate.
A182 F55 Slip On Flange Specifications
ASTM A182 F55 Slip On Flanges are available in the following specifications:
1/2"NB to 24"NB per ASME B16.5; larger patterns and EN 1092-1 super duplex flanges to order
Class
150#, 300#, 400#, 600#, 900#, 1500#, 2500#
Facing
Raised Face (SORF) — default; Flat Face or RTJ where the piping class specifies
Heat Treatment
Solution annealed per ASTM A182, thermal record retained
Service
Severe seawater, firewater, brine & sour duty — typically -50 °C to +250 °C per project specifications
Installation
Two fillet welds (hub + bore), pipe set back 1/8"; matching super duplex filler, tight heat-input control, no preheat, no PWHT
Sour Service
NACE MR0175 / ISO 15156 listed material family — supplied with hardness verification within the standard's limits
Certification
EN 10204 3.1 (standard) / 3.2 witnessed; G48 corrosion & ferrite testing where specified
Equivalent Grades of ASTM A182 F55
Standard
ASME
UNS
Werkstoff Nr.
EN
Common Name
ASTM A182 F55
SA182 F55
S32760
1.4501
X2CrNiMoCuWN25-7-4
Zeron 100
System partners: ASTM A790 super duplex pipe and A815 fittings in the same UNS number. Note the distinction from F53's Werkstoff 1.4410 — the two super duplexes carry different numbers and are specified by name. Certificates always state the actual grade forged.
Why A182 F55 Slip Ons Are Specified
PREN ≥ 40, Guaranteed on Paper
S32760 is the only common flange grade whose specification mandates the super duplex threshold on every heat — the certificate proves it, not just the recipe.
Tungsten Guards the Crevices
Flange faces, gasket seats and bolt holes are where seawater attacks first — the tungsten addition reinforces the passive film exactly there.
Copper Buys Acid Tolerance
Sulphuric contamination, acidified seawater and oilfield chemicals punish plain Cr-Mo-N grades — Zeron 100's copper widens the envelope.
North Sea Proven
Decades of firewater ring mains, seawater lift and injection systems stand behind the grade — operator specifications name it from heritage, not fashion.
Know the Handoffs
Milder chloride duty: F51/2205. The competing 2507 recipe: F53. Above the duplex ceiling or in strong reducing acids: nickel alloys. Critical RT-mandated lines: F55 weld necks.
How Our A182 F55 Slip On Flanges Are Manufactured
1
Forging — cut billet of certified A182 F55 heat is hot-forged into the flange blank, keeping full heat traceability from raw material to despatch.
2
Solution annealing — heated and rapidly quenched per ASTM A182 to restore the balanced austenite-ferrite structure and dissolve sigma phase — the critical step at 25% chromium; furnace record retained.
3
Machining — hub, faces and bolt holes to ASME B16.5; the bore machined slightly over pipe OD per the slip-on tolerance.
4
Facing & finish — SORF raised face with serrated stock finish, flat face or RTJ groove; pickled and passivated on request.
5
Testing & marking — mechanical, chemical and hardness verification against the heat, PREN confirmed ≥ 40; ASTM G48 corrosion and ferrite testing where the order specifies; then permanent marking of grade, size, class and heat number.
6
Certification & packing — EN 10204 3.1 MTC (3.2 witnessed on request), export-packed as pictured on this page.
Where A182 F55 Slip On Flanges Are Used
The severest chloride and sour services: offshore firewater ring mains and deluge systems, seawater lift and injection piping, subsea manifolds and topside process systems, high-pressure desalination (SWRO), hot brine and chlorinated circuits, scrubbers, and sour injection duty under NACE MR0175. Our F55 production below:
A182 F55 Super Duplex Flange — Machined & MarkedF55 Super Duplex Flanges — At Our WorksF55 (S32760) Super Duplex Flange — 4″ Class 150, Laser-Marked
A182 F55 Slip On Flange Dimensions
F55 slip-on dimensions follow the ASME B16.5 slip-on tables — identical for every material. Full charts by class:
Example: “Slip On Flange, 4″ NB, ASME B16.5 Class 300, RF, ASTM A182 F55 (S32760), EN 10204 3.1 — 20 pcs.” Quotations normally within 24 hours with price, unit weight and delivery.
ASTM A182 F55 Slip On Flanges — Frequently Asked Questions
What is an ASTM A182 F55 slip on flange?
It is a slip-on flange forged from ASTM A182 F55 — super duplex Zeron 100 (UNS S32760) — dimensioned to ASME B16.5. The flange slides over the pipe end and is secured with two fillet welds, and the chemistry is a 25Cr super duplex reinforced with deliberate copper and tungsten, with a pitting resistance number (PREN) of 40 or more guaranteed on every heat. It serves severe seawater, firewater and sour injection duty — the North Sea heritage grade.
What is Zeron 100?
The trade name under which UNS S32760 was developed and made famous — a super duplex stainless steel originating in the UK and proven across decades of North Sea seawater and firewater systems. ASTM A182 F55 is its forging designation. The recipe pairs the 25Cr-7Ni super duplex base with copper for resistance to reducing acids and tungsten for crevice-corrosion resistance, and uniquely writes the PREN ≥ 40 requirement into the material specification itself.
What is the chemical composition of ASTM A182 F55?
Per ASTM A182 for UNS S32760: carbon 0.030% max, manganese 1.00% max, silicon 1.00% max, phosphorus 0.030% max, sulphur 0.010% max, chromium 24.0-26.0%, nickel 6.0-8.0%, molybdenum 3.0-4.0%, nitrogen 0.20-0.30%, copper 0.50-1.00% and tungsten 0.50-1.00% — plus the specification's own requirement that PREN = %Cr + 3.3(%Mo + 0.5×%W) + 16×%N be 40 or higher on every heat. The copper and tungsten are deliberate additions, not residuals.
What are the mechanical properties of A182 F55 slip on flanges?
Per ASTM A182: tensile strength 750 MPa (109 ksi) minimum, yield strength 550 MPa (80 ksi) minimum and elongation 25% minimum in 2" — roughly triple the yield of 316L with the ductility of a solution-annealed duplex. Hardness is verified against the standard and, for sour lots, against the NACE MR0175 limits. Values are demonstrated per heat on the EN 10204 certificate.
Why does F55 contain copper and tungsten?
Each element patches a specific weakness of chloride-focused super duplex. Copper improves resistance to reducing acids — sulphuric acid contamination, acidified seawater, oilfield chemicals — where plain Cr-Mo-N grades suffer. Tungsten strengthens the passive film in tight crevices — flange faces, gasket seats, bolt holes — the exact geometry where seawater attacks first, and it earns a place in the PREN formula at half molybdenum's weight. Together they broaden Zeron 100's envelope beyond straight chloride pitting.
What is the difference between F55 (S32760) and F53 (S32750)?
Two competing super duplex recipes with the same mission. F53 / 2507 reaches its PREN with chromium, molybdenum and nitrogen alone; F55 / Zeron 100 adds copper and tungsten for extra crevice and reducing-acid resistance, and is the only one whose specification guarantees PREN ≥ 40 on every heat. Strength and applications overlap almost completely — projects typically standardise on one, often by operator heritage. We forge both; specify whichever your piping class names.
When is F55 chosen over duplex F51/2205?
When the chloride duty gets hotter or harsher than 2205's PREN of ~34 can hold: seawater above roughly ambient temperature, stagnant or chlorinated seawater such as firewater ring mains, hot high-chloride brines, and crevice-prone geometries. F55's guaranteed PREN of 40+ moves the critical pitting and crevice temperatures decisively upward. Where 2205 survives, it remains the more economical choice — water chemistry and temperature make the decision.
What temperature range can F55 super duplex slip on flanges handle?
Roughly -50 °C to +250 °C in common specification practice — the same deliberately narrow window as all duplex grades. The high chromium and molybdenum that buy the corrosion resistance also accelerate embrittling phases: 475 °C embrittlement of the ferrite and sigma-phase precipitation at 700-900 °C form quickly in super duplex, so the temperature cap is enforced, not advisory. Inside the window, F55 is among the most capable chloride-service materials money buys.
Why is super duplex the standard for seawater and firewater systems?
Because its critical pitting and crevice temperatures sit above real seawater service conditions. Warm, chlorinated or stagnant seawater — exactly what a firewater ring main holds — initiates pitting in 316L quickly and in 2205 eventually; PREN 40+ super duplex holds its passive film through it, and F55's tungsten specifically reinforces the crevices where attack starts. Add 550 MPa yield for weight-critical offshore topsides, and super duplex became the default seawater flange material.
How is an A182 F55 slip on flange welded to pipe?
With two fillet welds — hub outside, bore inside, pipe set back 1/8" (3 mm) — using matching over-alloyed super duplex filler (Zeron 100X type or ER2594) and tightly controlled heat input, typically 0.5-1.5 kJ/mm with interpass below about 100-150 °C. The window is tight because sigma phase forms fast at 25% chromium. No preheat and no PWHT — anything other than a full solution anneal harms super duplex. Qualified duplex welders and ferrite checks are normal practice.
What is the equivalent of ASTM A182 F55 in other standards?
ASME SA182 F55 is the boiler-code twin; UNS S32760 the designation; EN X2CrNiMoCuWN25-7-4 (Werkstoff 1.4501) the European equivalent — all describing the alloy marketed as Zeron 100. System partners specified alongside it: ASTM A790 super duplex pipe and A815 fittings in the same UNS number. Certificates always state the actual grade forged. Note the distinction from F53's 1.4410 — the two super duplexes carry different Werkstoff numbers.
Is A182 F55 suitable for sour service under NACE MR0175?
Yes — super duplex is a listed material family in NACE MR0175 / ISO 15156, and S32760's copper-tungsten chemistry has a long record in sour injection and produced-fluid systems, subject to the standard's grade-specific limits on hardness, H2S partial pressure, chloride level and temperature. Solution-annealed forgings with verified hardness fit within those limits. State the NACE requirement and the service conditions on the enquiry, and the flanges ship documented accordingly.
What sizes and classes are A182 F55 slip on flanges available in?
From ½" to 24" NB per ASME B16.5 in Classes 150 through 2500, with larger patterns and EN 1092-1 super duplex flanges forged to order. Super duplex is strictly project material, so flanges are forged against the order — standard sizes normally dispatch within a few weeks with EN 10204 3.1 certification. State the required delivery on the enquiry and we confirm the schedule with the quotation.
What details are needed to get an accurate A182 F55 slip on flange quotation?
Five elements plus commercial terms: (1) size and standard — e.g. 4" NB ASME B16.5; (2) pressure class — 150 through 2500; (3) facing — SORF (raised face) default, flat face or RTJ where specified; (4) grade — ASTM A182 F55 (S32760), NACE MR0175 where sour, plus any corrosion or ferrite testing the project specifies; (5) certification — EN 10204 3.1 or 3.2. No pipe schedule is needed for the slip-on bore. Add the quantity and destination and we return price, weight and delivery.
Who manufactures ASTM A182 F55 slip on flanges in India?
Tesco Steel & Engineering is an ISO 9001:2015 certified flange manufacturer based in Mumbai, India, forging ASTM A182 F55 super duplex Zeron 100 slip on flanges from ½" to 24" NB per ASME B16.5 — alongside F53 super duplex and the F51/F60 duplex grades — in solution-annealed condition with full heat traceability and EN 10204 3.1/3.2 certification on every lot. Flanges are marked with grade, size, class and heat number and export to more than 50 countries.
