Stainless Steel Flanges Manufacturer & Supplier | ASTM A182

Stainless Steel Flanges Manufacturer, Stockist and Exporter In India

Solitaire Overseas is a well-known manufacturer of stainless steel flanges in India, and a reputable supplier and exporter of quality SS flanges. These elements are usually referred to as stainless steel pipe flanges, which are essential in the production of robust and stable joints in piping systems and industrial equipment. The stainless steel flanges are highly favored over the carbon steel flanges because they have better corrosion resistance, high strength and durable service life.

We specialize in producing ASTM A182 stainless steel flanges in various sizes, grades and specifications that satisfy various industrial demands. We have a range of products such as Weld Neck Flanges, Slip-On Flanges, Blind Flanges, Socket Weld Flanges, Threaded Flanges, Lap Joint Flanges and Ring Type Joint (RTJ) Flanges. Premium grades that we also provide include SS 304 flanges, SS 316 flanges, which have good performance and durability in harsh conditions.

We are a reputable supplier of stainless steel flanges, with international certifications, exporting to various countries and a well developed distribution network. Our current production plant can make flanges that are 1/2 inch to 40 inches in diameter.

Our products are all in line with the international specifications like ANSI/ASME, EN, DIN and JIS. The common material grades are ASTM A182 F304/L and F316/L with a pressure rating of Class 150 to Class 2500. These standards guarantee a high level of suitability in critical use in oil and gas, petrochemical, power generation and offshore industries.

We owe our dedication to quality to our high quality control mechanisms and certifications and make us a favorite stainless steel flanges exporter across the globe. Solitaire Overseas keeps providing competitive piping solutions to high performance at reasonable rates.

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What are Stainless Steel Flanges (SS Flanges)?

Stainless steel flanges are essential components used to connect pipes, valves, pumps, and other equipment in a piping system. They ensure a leak-proof and secure connection, enabling efficient flow of fluids, gases, or steam. Compared to carbon steel, stainless steel flanges provide enhanced corrosion resistance, strength, and durability, making them ideal for harsh environments such as chemical processing, marine, and oil & gas industries.

The corrosion resistance of stainless steel flanges comes from their chromium content (minimum 10.5%), which forms a protective oxide layer on the surface. Additional alloying elements like nickel and molybdenum further enhance resistance against chlorides, acids, and seawater, ensuring long-term performance with minimal maintenance.

Stainless Steel Flanges (SS Flanges) Specifications

Material Standard	ASTM A182 / ASME SA182
Size Range	NPS: 1/2" to 40 \| NB: 15 NB to 1000 NB
Grades	F: 304, 304L, 304H, 304N, 304LN, 316, 316L, 316H, 316Ti, 316N, 316LN, 310, 317, 317L, 321, 321H, 347, 347H, 904L Duplex/Super Duplex: F-51, 53, 55, 60, 68
Standards	ANSI/ASME B16.5, B16.47 Series A & B, B16.48, EN-1092, DIN, BS4504, BS 10, ASTM, ASME
Types	SO, WN, SW, BL, THRD, Lap Joint, Orifice Type, Reducing Flanges, Spectacle Blind
Class / Pressure Rating	ANSI/ASME: 150#, 300#, 400#, 600#, 900#, 1500#, 2500# DIN/EN: PN6, PN10, PN16, PN25, PN40, PN63, PN100

Stainless Steel Flanges Chemical Composition

Type	C	Mn	P	S	Si	Cr	Ni	Mb
302	0.15	2.00	0.045	0.030	1.00	17.00/19.00	8.00/10.00	–
304	0.08	2.00	0.045	0.030	1.00	18.00/20.00	8.00/10.50	–
304L	0.03	2.00	0.045	0.030	1.00	18.00/20.00	8.00/12.00	–
309	0.20	2.00	0.045	0.030	1.00	22.00/24.00	12.00/15.00	–
309S	0.08	2.00	0.045	–	1.00	22.00/24.00	–	–
310	0.25	2.00	0.045	0.030	1.5	24.00/26.00	19.00/22.00	–
310S	0.08	2.00	0.045	0.030	1.5	24.00/26.00	19.00/22.00	–
316	0.08	2.00	0.045	0.030	1.00	16.00/18.00	10.00/14.00	2.00/3.00
316L	0.03	2.00	0.045	0.030	1.00	16.00/18.00	10.00/14.00	2.00/3.00
317	0.08	2.00	0.045	0.030	1.00/1.00	18.00/20.00	11.00/15.00	3.00/4.00
317L	0.03	2.00	0.045	0.030	0.75	18.00/20.00	11.00/15.00	3.00/4.00
321	0.08	2.00	0.040	0.030	1.00	17.00/19.00	9.00/12.00	0.75/0.75
347	0.08	2.00	0.040	0.030	0.5/1.00	17.00/19.00	9.00/12.00	0.5/0.75

Stainless Steel Pipe Flanges Mechanical Properties

Type	UNS	Tensile (ksi) min	Yield (ksi) min	Elongation min	Hardness (Brinell) max	Hardness (Rockwell B) max
302	S30200	75	30	40% in 2″	183	88
304	S30400	75	30	40% in 2″	183	88
304L	S30403	70	30	40% in 2″	183	88
309	S30900	75	30	40% in 2″	217	95
309S	S30908	75	30	40% in 2″	217	95
310	S31000	75	30	40% in 2″	217	95
310S	S31008	75	30	40% in 2″	217	95
316	S31600	75	30	40% in 2″	217	95
316L	S31603	70	25	35% in 2″	217	95
317	S31700	75	30	35% in 2″	217	95
317L	S31703	75	30	35% in 2″	217	95
321	S32100	75	30	40% in 2″	183	88
347	S34700	75	30	40% in 2″	183	88

Heat Treatment for Stainless Steel Flanges

Heat Treatment Process	Application	Purpose
Solution Annealing	Austenitic grades (e.g., 304, 316)	Dissolves chromium carbides, relieves internal stress, maximizes corrosion resistance and ductility.
Stabilization	Stabilized grades (e.g., 321, 347)	Prevents sensitization and intergranular corrosion by combining carbon with stabilizing elements.
Duplex & Super Duplex Treatment	Duplex and Super Duplex grades	Achieves a balanced ferrite-austenite microstructure for high strength and corrosion resistance.

Stainless Steel Plate Flange Pressure Rating

Temperature (°F)	150#	300#	400#	600#	900#	1500#	2500#
-20 to 100	275	720	960	1440	2160	3600	6000
200	230	600	800	1200	1800	3000	5000
300	205	540	720	1080	1620	2700	4500
400	190	495	660	995	1490	2485	4140
500	170	465	620	930	1395	2330	3880
600	140	435	580	875	1310	2185	3640
650	125	430	575	860	1290	2150	3580
700	110	425	565	850	1275	2125	3540
750	95	415	555	830	1245	2075	3460
800	80	405	540	805	1210	2015	3360
850	65	395	530	790	1190	1980	3300
900	50	390	520	780	1165	1945	3240
950	35	380	510	765	1145	1910	3180
1000	20	320	430	640	965	1605	2675
1050	20	310	410	615	925	1545	2570
1100	20	255	345	515	770	1285	2145
1150	20	200	265	400	595	995	1655
1200	20	155	205	310	465	770	1285
1250	20	115	150	225	340	565	945
1300	20	85	115	170	255	430	715
1350	20	60	80	125	185	310	515
1400	20	50	65	95	145	240	400
1450	15	35	45	70	105	170	285
1500	10	25	35	55	80	135	230

Stainless Steel Grades for Flanges

At Solitaire Overseas, we specialize in manufacturing flanges from the most popular and reliable stainless steel grades, ensuring you get the perfect material for your specific needs.

Stainless Steel 304 Flanges

Stainless Steel 316 Flanges

Stainless Steel 904L Flanges

Types Of Stainless Steel Flanges (SS Flanges)

As a leading stainless steel flanges manufacturer in India, we produce a wide variety of flanges to suit different pressure ratings, sizes, and connection types. Our product range includes:

Blind Flange

A Blind Flange is a solid, circular plate with boltholes but no center hole, used to seal the ends of piping systems and pressure vessels. It allows easy access for inspections and maintenance.

Weld Neck Flange

Designed for high-pressure applications, Weld Neck Flanges have a long tapered hub that minimizes stress at the flange base. The smooth transition enhances durability and reduces turbulence.

Slip-On Flange

A Slip-On Flange is slid over the pipe and welded both inside and outside. These cost-effective flanges require less precision in pipe cutting and are ideal for low-pressure applications.

Socket Weld Flange

Socket Weld Flanges involve inserting the pipe into the socket end before welding, ensuring a smooth bore and enhanced fluid or gas flow. Mainly used for smaller, high-pressure pipelines.

Threaded Flange

Threaded Flanges resemble slip-on flanges but feature tapered threads for easy connection without welding. Commonly used in low-pressure systems with externally threaded pipes.

Lap Joint Flange

A Lap Joint Flange slides over the pipe and is typically used with stub end fittings. It allows easy rotation and frequent dismantling, ideal for applications requiring regular maintenance.

Manufacturing Process of Stainless Steel Flanges

Stainless steel flanges are manufactured using advanced forging and machining processes to ensure high strength and dimensional accuracy.

Raw Material Selection: High-quality billets conforming to ASTM A182 standards are selected.
Forging Process: The material is heated and forged into the desired shape to enhance grain structure and strength.
Heat Treatment: Processes such as solution annealing improve corrosion resistance and mechanical properties.
Machining: CNC machining ensures precise dimensions, bore alignment, and surface finish.
Drilling & Finishing: Bolt holes are drilled, and surface finishing is applied as per specifications.
Inspection: Each flange undergoes strict quality checks before dispatch.

Testing & Inspection of Stainless Steel Flanges

To ensure quality and compliance, all stainless steel flanges undergo rigorous testing procedures:

PMI Testing (Positive Material Identification)
Ultrasonic Testing (UT)
Radiographic Testing (RT)
Hydrostatic Testing
Hardness Testing
Chemical Analysis
Dimensional Inspection

These tests ensure that flanges meet international standards and perform reliably in critical applications.

Flange Facing Types

Different flange facing types are available to suit sealing requirements:

Raised Face (RF) – Most commonly used for general applications
Flat Face (FF) – Suitable for low-pressure systems
Ring Type Joint (RTJ) – Designed for high-pressure and high-temperature conditions
Tongue & Groove (T&G) – Provides enhanced sealing performance
Male & Female (M&F) – Ensures proper alignment and sealing

Applications of Stainless Steel Flanges (SS Flanges)

Pipeline systems and engineering
Oil & Gas sector
Mechanical and plant engineering
Marine and offshore operations
Wastewater treatment plants
Chemical and petrochemical processing
Power generation industry
Aerospace applications
Food and beverage processing
And many other industrial uses

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Why Choose Solitaire Overseas for Stainless Steel Flanges?

Our stainless steel flanges undergo rigorous testing, including PMI, ultrasonic testing, and chemical analysis, ensuring compliance with ASTM A182 and global standards.
We offer competitive pricing without compromising quality, making us a preferred stainless steel flanges manufacturer and supplier in India.
Our extensive inventory includes SS 304, SS 316, and duplex stainless steel flanges, ensuring quick delivery for both standard and customized requirements.
We provide customized flange solutions based on client drawings and specifications, ensuring precise application fit.

Stainless Steel Pipes

Stainless Steel Tubes

Stainless Steel Pipe Fittings

Stainless Steel Buttweld Fittings

Stainless Steel Forged Fittings

Get a Quote for Stainless Steel Flanges

Looking to buy high-quality stainless steel flanges? Contact us today to discuss your requirements and receive a competitive quote. Our team ensures fast response, technical support, and reliable delivery.

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Stainless Steel Flange Price List

Piece / Specification	Price (INR)	Price (UAE Dirham)	Price (Saudi Riyal)
ASME SA 182 SS Slip On Flange	5,938	19.90	20.32
Stainless Weld Neck Rf Flange	12,476	24.60	25.13
Stainless Steel A 182 Weld Neck Flange	3,811	41.92	42.81
Stainless Steel Blind Flange	6,048	25.17	25.71

Frequently Asked Questions

Stainless steel flanges are used to connect pipes, valves, pumps, and other equipment in a piping system. They create a secure, leak-proof joint that allows easy assembly, disassembly, maintenance, and inspection in industries such as oil & gas, chemical processing, and water treatment.

The three commonly used types of stainless steel flanges are Weld Neck Flanges, Slip-On Flanges, and Socket Weld Flanges. Each type is designed for specific pressure levels and applications, with weld neck flanges used for high-pressure systems and slip-on flanges for low-pressure applications.

Stainless steel flanges are typically manufactured from ASTM A182 grades, including F304/F304L and F316/F316L. These grades offer excellent corrosion resistance, strength, and durability, making them suitable for a wide range of industrial applications.

The most widely used standard is ASTM A182, which covers forged or rolled alloy and stainless steel pipe flanges, fittings, valves, and parts for high-temperature service. Common materials under this standard include ASTM A182 F304/L and F316/L.

Stainless steel flanges are available in pressure classes such as Class 150, 300, 400, 600, 900, 1500, and 2500. The pressure rating depends on the material grade, flange type, and operating temperature.

Slip-on flanges are designed to slide over the pipe and are welded both inside and outside, making them easier to install and cost-effective. Weld neck flanges have a long tapered hub that provides better strength and stress distribution, making them ideal for high-pressure and high-temperature applications.

Common grades used in stainless steel flanges include 304, 304L, 316, 316L, 321, 347, and 904L. Duplex and super duplex grades are also used for applications requiring higher strength and corrosion resistance.

ANSI flange standards (now governed by ASME B16.5 and ASME B16.47) define the dimensions, pressure ratings, materials, and tolerances for flanges used in piping systems, ensuring compatibility and safety.

Stainless steel flanges are manufactured through a process that includes forging, heat treatment, machining, drilling, and finishing. Each flange is then tested using methods such as PMI, ultrasonic testing, and dimensional inspection to ensure quality and compliance with standards.