Duplex Steel UNS S31803 Forged Fittings Manufacturer & Supplier

Midland Alloys Inc., a reputable Indian manufacturer and international supplier of duplex steel forged fittings supplying industries all over the world with high quality, precisely engineered products. Our Duplex Steel UNS S31803 Forged Fittings are forged from high grade duplex stainless steel, combining austenitic and ferritic structures for excellent corrosion resistance and high mechanical strength. These fittings provide outstanding performance in chemically aggressive and marine environments, making them perfect for high-pressure and high-temperature settings. Our S31803 forged fittings satisfy strict industry standard such as ASTM A182 and ASME SA182 and come in pressure classes of 2000 LBS, 3000 LBS, 6000 LBS and 9000 LBS. These fittings have strong structural integrity and a precise chemical composition that include 22.0–23.0% Cr, 4.5–6.5% Ni and 3.0–3.5% Mo. They also have melting points between 1420 and 1465°C. Depending on the product and delivery requirements we guarantee safe packaging in wooden boxes, pallets, shrink-wrap or cartons.

Benefits of ASTM A182 F51 (S31803) Forged Fittings

For demanding industrial applications, Duplex Steel S31803 Forged Pipe Fitting is a great option because of their combination of mechanical strength and corrosion resistance.

Outstanding resistance to general corrosion, especially in chloride rich environments
High resistance to stress corrosion cracking (SCC) under tension and corrosive media
Excellent pitting and crevice corrosion protection due to duplex microstructure
Superior performance in marine or coastal applications prone to chloride attack
Higher tensile and yield strength than many stainless steels
Tough and durable under dynamic and impact loads
Great fatigue strength for cyclic or vibration-based applications
Excellent weldability and easy fabrication for complex system designs
Cost-effective material solution due to longer life and reduced maintenance

Difference Between Duplex Steel S31803 & S32205 Forged Fittings

The main distinction between Duplex Steel S31803 and S32205 Forged Fittings lies in their chemical composition. S32205 contains slightly higher levels of chromium, molybdenum, and nitrogen, which improves its corrosion resistance, particularly in harsh chloride-containing environments. This enhancement also contributes to slightly better mechanical strength and weldability. S32205 is typically chosen for more aggressive corrosion setting while S31803 is still a dependable and affordable choice for standard duplex applications even though both grades satisfy the duplex standard and are interchangeable in many application.

Specification of Duplex Steel UNS S31803 Forged Fittings

Types of Duplex Steel UNS S31803 Forged Fittings

Manufacturing Types

Threaded Forged Fittings

Designed with internal or external threads, these fittings allow quick assembly and disassembly without welding.
Socket Weld Forged Fittings

These fittings are joined by inserting the pipe into a recessed area of the fitting and welding around it, ensuring strong, leak-proof joints.
Screwed Fittings

Similar to threaded types, screwed fittings are connected using screw threads, making installation simple and cost-effective.
BSPT

Bushings help reduce the bore size in a fitting or valve connection by joining pipes of varying diameters.
NPT

End caps are used to seal a pipeline's end, shielding it from impurities and guaranteeing closed systems' safety.

Forms

Forged Elbow

Elbows, which come in 45° and 90° varieties shift the direction of flow with little pressure loss.
Forged Bushing

Bushings help reduce the bore size in a fitting or valve connection by joining pipes of varying diameters.
Forged Tee

Used to split or combine flow across three directions essential for branching pipeline.
Forged Coupling

Offer a safe connection between two pipes; threaded and socket-welded options are available.
Forged Plug

Close open pipe ends which are frequently used for isolation or testing.
Forged Cross

With four openings, cross fittings help connect four pipes used when fluid distribution needs to occur in multiple directions.

Contact Midland Alloys Inc. for Your Duplex Steel UNS S31803 Forged Fittings Needs

Contact us today to discuss how Duplex Steel UNS S31803 Forged Fittings can benefit your application. Whether you need guidance in selecting the right pipes or have specific requirements, our team of experts is here to help you find the optimal solution.

Technical Details & Delivery Condition

Chemical Composition of Duplex Steel UNS S31803 Forged Fittings

Grade	C	Mn	Si	P	S	Cr	Mo	Ni	N	Fe
31803	0.030 max	2.00 max	1.00 max	0.030 max	0.020 max	21.0 – 23.0	2.50 – 3.50	4.50 – 6.50	0.8 – 0.20	63.54 min

Mechanical Properties of Duplex Steel UNS S31803 Forged Fittings

Grades	Density (g/cm³)	Melting Point	Tensile Strength (MPa) min	Yield Strength 0.2% Proof (MPa) min	Elongation (% in 50mm) min
31803	7.8 g/cm³	1350 °C (2460 °F)	Psi – 116000 , MPa – 800	Psi – 80000 , MPa – 550	15 %

Duplex Steel UNS S31803 Forged Fittings Equivalent Grade

STANDARD	WERKSTOFF NR.	UNS
Duplex S31803	1.4462	S31803 / S32205

Duplex & Super Duplex Steel Forged Fittings Grades We Offer

Duplex Steel Forged Fittings

Duplex Steel UNS S31803 Forged Fittings

Duplex Steel UNS S32205 Forged Fittings

Super Duplex Steel Forged Fittings

Super Duplex Steel UNS S32750 Forged Fittings

Super Duplex Steel UNS S32760 Forged Fittings

Socket Weld Fittings Dimensions

Threaded Fittings Dimensions

Tolerance Chart

Socket Weld Fittings Dimensions

Threaded Fittings Dimensions

Tolerance Chart

Manufacturing Process of Duplex Steel UNS S31803 Forged Fittings

Raw Material

Cutting

Sizing

Heat Treatment

Pickling

Beveling

Polishing

Sand Blasting

Pickling / Passivating

Inspection

Analytic

Marking

Packing & Shipping

Applications of Welded/Threaded S31803 Forged Pipe Fittings

Welded and Threaded S31803 Duplex Steel Forged Pipe Fittings serve a wide range of industrial operations where strength, corrosion resistance and long term durability are crucial. These fittings are widely used in oil refinery equipment, industrial boilers, pressure vessels, and chemical and pharmaceutical processing systems.They guarantee safe corrosion resistant connection in chemical heat exchangers and petrochemical refineries. While nuclear power plants, food processing facilities, and water pipelines depend on their hygienic compliance and resistance to high temperatures, the paper and pulp industry benefit from their capacity to withstand strong bleaching agent. They are perfect for boiler systems, desalination plants and pipeline networks where continuous operation under fluctuating loads is typical due to their high fatigue resistance.

Offshore Industry

Nuclear Industries

Refineries

Ship Building

Aerospace

Pharmaceutical

Why choose us for S31803 Duplex Steel Forged Fittings

We are a reputable Indian manufacturer and exporter of UNS S31803 Duplex Steel Forged Fittings, which are renowned for their accuracy, dependability and quality. We follow strict ASTM A182, ASME SA182, and EN standards with ISO-certified manufacturing practices. To guarantee total compliance and traceability our products go through both internal and external testing, such as PMI, tensile strength, chemical analysis and pitting resistance tests. We offer customizations like specific sizes, end finishes, and surface treatments. We guarantee fast delivery and comprehensive customer support because of our robust supply network that spans the Gulf nations, Europe, Africa and Southeast Asia. Supported by Mill Test Certificates (MTCs) we place a high value on enduring relationships through trust, quality, and service.

FAQs – Duplex Steel UNS S31803 Forged Fittings

What is the maximum working pressure for Duplex S31803 Forged Pipe Fittings?

As long as temperature and system compatibility are taken into consideration, the maximum pressure is established by the class rating. Up to 9000 LBS class support extremely high pressure applications.

Are S31803 Forged Fittings suitable for seawater applications?

Yes, they are perfect for offshore and marine environments due to their high resistance to localized corrosion and chlorides.

What surface finishes are available for Duplex Stainless Steel Forged Fittings?

Standard finishes include plain, pickled, or custom polished surfaces, based on client specifications.

What testing is done on Duplex S31803 Forged Fittings before dispatch?

We conduct spectro analysis, mechanical tests, hardness tests, and pitting resistance testing, along with full traceability documentation.

What is the price range of Duplex S31803 Forged Fittings per kg in India?

Duplex S31803 Forged Fittings Price per kg may vary based on size, class, and quantity—please contact us for the latest price list and stock availability.

Can S31803 Fittings be used in high-temperature pipelines?

Yes, they perform well in moderately high temperatures, with a melting range of 1420–1465°C, making them suitable for heat-exposed operations.

Are Duplex S31803 and 2205 Forged Fittings the same?

Yes, UNS S31803 and UNS S32205 are often referred to under the 2205 Duplex grade, though S32205 has marginally better corrosion resistance.

Nominal Size		Socket Bore Dia	Bore Dia of Fittings			Socket Wall Thickness						Body Wall			Depth of Socket	Center to Bottom of Socket
D N	NPS	B	D			C						Gmin			J min	A
			3000	6000	9000	3000		6000		9000		3000	6000	9000		90° Elbow Tee Cross			45° Elbow
			3000	6000	9000	ave	min	ave	min	ave	min	3000	6000	9000		3000	6000	9000	3000	6000	9000
6	1/8	10.9	6.1	3.2		3.18	3.18	3.96	3.43			2.41	3.15		9.5	11.0	11.0		8	8
8	1/4	14.3	8.5	5.6		3.78	3.30	4.60	4.01			3.02	3.68		9.5	11.0	13.5		8	8
10	3/8	17.7	11.8	8.4		4.01	3.50	5.03	4.37			3.20	4.01		9.5	13.5	15.5		8.0	11.0
15	1/2	21.9	15.0	11	5.6	4.67	4.09	5.97	5.18	9.53	8.18	3.73	4.78	7.47	9.5	15.5	19.0	25.5	11	12.5	15.5
20	3/4	27.3	20.2	14.8	10.3	4.90	4.27	6.96	6.04	9.78	8.56	3.91	5.56	7.82	12.5	19.0	22.5	28.5	13	14	19
25	1	34	25.9	19.9	14.4	5.69	4.98	7.92	6.93	11.38	9.96	4.55	6.35	9.09	12.5	22.5	27.0	32.0	14.0	17.5	20.5
32	1-1/4	42.8	34.3	28.7	22.0	6.07	5.28	7.92	6.93	12.14	10.62	4.85	6.35	9.70	12.5	27.0	32.0	35.0	17.5	20.5	22.5
40	1-1/2	48.9	40.1	33.2	27.2	6.35	5.54	8.92	7.8	12.70	11.12	5.08	7.14	10.15	12.5	32.0	38.0	38.0	20.5	25.5	25.5
50	2	61.2	51.7	42.1	37.4	6.93	6.04	10.92	9.5	13.84	12.12	5.54	8.74	11.07	16.0	38.0	41.0	54.0	25.5	28.5	28.5
65	2-1/2	73.9	61.2			8.76	7.62					7.01			16.0	41.0			28.5
80	3	89.9	76.4			9.52	8.30					7.62			16.0	57.0			32.0
100	4	115.5	100.7			10.69	9.35					8.56			19.0	66.5			41.0

Nominal Size		Center-to-End						Outside Diameter of Band			Wall Thickness			Length of Thread
DN	NPS	A						H			G min			min	mim
		90° Elbows, Tees, Crosses			45° Elbows			H			G min
		2000	3000	6000	2000	3000	6000	2000	3000	6000	2000	3000	6000
6 8 10	1/8 1/4 3/8	21 21 25	21 25 28	25 28 33	17 17 19	17 19 22	19 22 25	22 22 25	22 25 33	25 33 38	3.18 3.18 3.18	3.18 3.30 3.51	6.35 6.60 6.98	6.4 8.1 9.1	6.7 10.2 10.4
15 20 25	1/2 3/4 1	28 33 38	33 38 44	38 44 51	22 25 28	25 28 33	28 33 35	33 38 46	38 46 56	46 56 62	3.18 3.18 3.68	4.09 4.32 4.98	8.15 8.53 9.93	10.9 12.7 14.7	13.6 13.9 17.3
32 40 50	1-1/4 1-1/2 2	44 51 60	51 60 64	60 64 83	33 35 43	35 43 44	43 44 52	56 62 75	62 75 84	84 102	3.89 4.01 4.27	5.28 5.56 7.14	10.59 11.07 12.09	17.0 17.8 19.0	18.0 18.4 19.2
65 80 100	2-1/2 3 4	76 86 106	83 95 114	95 106 114	52 64 79	52 64 79	64 79 79	92 109 146	102 121 152	121 146 152	5.61 5.99 6.55	7.65 8.84 11.18	15.29 16.64 18.67	23.6 25.9 27.7	28.9 30.5 33.0

Minimal Diam.		Outer Dia. For Bevel End	Inner Dia. For End	Elbow		Tee		Reducer	Cap	180° Elbow
DN	NPS			A	B	C	M	H	E	O	K	Roughness
500-600	20-24	+6.4/-4.8	4.8	3.2	3.2	3.2	3.2	4.8	9.6	–	–	–
650-750	26-30
				4.8	4.8	4.8	4.8
800-1200	32-48
1250-1500	50-60	+9.6/-6.4	6.4	9.6	9.6	9.6	9.6	9.6	–
1550-1750	62-70	+12.7/-9.6	9.6	12.7	12.7	–
1800-2000	72-80	+16/-12	12	16	16
15-65	1/2-2 1/2	+1.6/-0.8	0.8	1.6	1.6	1.6	1.6	1.6	3.2	6.4	6.4	0.8
80-100	3-4	1.6	1.6						6.4
125-200	5-8	+2.4/-1.6
250-450	10-18	+4/-3.2	3.2	2.4	2.4	2.4	2.4	2.4		9.6