On April 17, 2025, an old customer from China sent us an inquiry for ASTM A815 UNS S31803 Butt Weld Pipe Fittings, which is another manifestation of the trust between the two parties over the years. We immediately conducted a detailed analysis based on the drawings and technical requirements provided by the customer to ensure that we can provide accurate and professional solutions in the shortest time.

ZIZI is a professional manufacturer and processor of pipes and fittings, dedicated to providing high-quality products for core sectors such as chemical, petroleum, natural gas, water conservancy, electric power, and marine engineering. We offer a comprehensive range of pipes and fittings, including seamless pipes, welded pipes, butt weld fittings, high-pressure forged fittings, and flanges. Crucially, we also possess strong capabilities in producing machined parts, allowing us to customize products to meet specific client requirements. Our materials expertise covers a wide array, including carbon steel, stainless steel, alloy steel, low-temperature steel, duplex steel, and nickel-based alloys, ensuring we can satisfy demanding application needs across various harsh operating conditions.

Purchase List

ITEM	DESCRIPTION	QUANTITY	UNITS
1	Elbow/curva 90° LR SMLS A815 UNS S31803 Sch.40S diam.: 2 1/2	6	PCS
2	Elbow/curva 90° LR SMLS A815 UNS S31803 Sch.40S diam.: 4″	10	PCS
3	Conc Red/rid. conc. SMLS A815 UNS S31803 Sch.40S diam.: 2″ x 1 1/2″	5	PCS
4	Conc Red/rid. conc. SMLS A815 UNS S31803 Sch.40S diam.: 2 1/2″ x 2″	5	PCS
5	Conc Red/rid. conc. SMLS A815 UNS S31803 Sch.40S diam.: 4″ x 2″	4	PCS
6	Cap/Fondo bomb. Smls A815 S31803 Sch.40S diam.: 2 1/2″	4	PCS
7	Cap/Fondo bomb. Smls A815 S31803 Sch.40S diam.: 4″	4	PCS

ASTM A815 UNS S31803 Pipe Fitting Dimension Inspection

Outer Diameter (OD): Measure the outer diameter at both ends of the fitting to ensure it meets tolerance requirements.

Wall Thickness (WT): Measure the wall thickness at various points on the fitting (especially the outer and inner arcs of elbows, and the transition sections of reducers) to ensure it falls within the permissible deviation.

ASTM A815 UNS S31803 Pipe Fittings Specification

Specifications	ASTM A815 / ASME SA815
Dimensions	ASME/ANSI B16.9, ASME B16.28, MSS-SP-43
Grades	Duplex S31803, S32205
Size	1/2” NB to 24″NB in
Type	Seamless / Welded / Fabricated
Thickness	Sch 5s, Sch 10s, Sch 40s, Sch 80s, Sch 160s, Sch XXS

ASTM A815 UNS S31803 Chemical Composition

CHEMICAL	LIMITS	C	Mn	P	S	Si	Cr	Ni	Mo	N
ASTM A815 UNS 31803	MIN
MAX	0.03	2.0	0.030	0.020	1.0	23	6.5	3.5	0.20

ASTM A815 UNS S31803 Mechanical Property

MATERIAL	T.S (MPA)	Y.S (MPA)	EL %	HARDNESS
ASTM A815 UNS 31803	620 min	450 min	20 min	290 max

Equivalent Grades of ASTM A815 Duplex Steel Buttweld Fittings

JIS	KS	UNS	ISO	DIN EN/DIN W-Nr.	EN
SUS 329J3L	STS 329J3L	S31803	X2CrNiMoN 22-5-3	X2CrNiMoN 22-5-3	1.4462

Duplex S31803 Buttweld Pipe Elbow Dimension

DN	NPS	OD	A-LR	A-SR
15	1/2	21.3	38	25
20	3/4	26.7	38	25
25	1	33.4	38	25
32	1 1/4	42.2	48	32
40	1 1/2	48.3	57	38
50	2	60.3	76	51
65	2 1/2	73	95	64
80	3	88.9	114	76
90	3 1/2	101.6	133	89
100	4	114.3	152	102
125	5	141.3	190	127
150	6	168.3	229	152
200	8	219.1	305	203
250	10	273	381	254
300	12	323.8	457	305
350	14	355.6	533	356
550	22	559	838	559
600	24	610	914	610
650	26	660	991	660
700	28	711	1067	711
750	30	762	1143	762
800	32	813	1219	813
850	34	864	1295	864
900	36	914	1372	914
950	38	965	1447	965
1000	40	1016	1524	1016
1050	42	1067	1600	1067
1100	44	1118	1676	1118
1150	46	1168	1753	1168
1200	48	1219	1829	1219
1300	52	1321	1981	1321
1400	56	1422	2134	1422
1500	60	1524	2286	1524
1600	64	1626	2438	1626
1700	68	1727	2591	1727
1800	72	1829	2743	1829
1900	76	1930	2896	1930
2000	80	2032	3048	2032

Application Areas

Oil and gas industry: especially offshore platforms, gas gathering pipelines, crude oil and natural gas processing equipment, dealing with corrosive environments with high chloride ions and hydrogen sulfide.

Chemical and petrochemical industries: chlor-alkali industry, fertilizer production, acid treatment, seawater cooling systems, etc., dealing with various highly corrosive chemical media.

Desalination: Pipeline, pump and valve systems, resisting corrosion from high-concentration chloride seawater.

Pollution control equipment: Flue gas desulfurization (FGD) systems, handling hot and humid flue gas containing chlorides and sulfur oxides.

Pulp and paper industry: Equipment and pipelines in bleaching plants, resisting corrosion from chlorine-containing bleaching agents.

Structural applications: Structural components that require high strength and corrosion resistance.