Metinox Overseas is the Alloy 20 Pipe Fittings manufacturer and supplier in India, which provides a complete selection of an ASTM B366 / ASME SB366 buttweld and forged fittings to the most challenging corrosive service conditions. Our Alloy 20 Pipe Fittings are made of niobium-stabilized austenitic nickel-iron-chromium alloy (UNS N08020 / DIN 2.4660), designed to provide excellent performance in sulfuric acid in all concentrations, hot phosphoric acid, and chloride-bearing media as well as a wide spectrum of aggressive chemicals.
The characteristic feature of Alloy 20 Pipe Fittings as compared to normal 316L or 317L stainless steel fittings is that they are niobium stabilized. Niobium inhibits intergranular corrosion in heat-affected areas of a weld, and thus, requires no post-weld heat treatment (PWHT). This important fabrication benefit saves a lot of installation time and money and so Alloy 20 Buttweld Fittings is the choice in sulfuric acid plants, pharmaceutical reactors, pickling equipment, food processing lines and chemical process industries across the globe.
Metinox Overseas distributes Alloy 20 Pipe Fittings to its customers in UAE, Saudi Arabia, USA, UK, Singapore, South Africa and Australia. EN 10204 3.1 Mill Test Certificates are available on all fittings.
Request a quote now!All Alloy 20 Pipe Fittings supplied by Metinox Overseas conform to the following standards and specifications. Buyers specifying ASTM B366 Alloy 20 Fittings for sulfuric acid or chemical service should note the WP-20 (seamless) and WP-20-W (welded) grade designations, both of which are covered under our supply range.
| Specification Parameter | Details |
|---|---|
| Standard | ASTM B366 / ASME SB366 |
| Grade Designations | WP-20 (Seamless) and WP-20-W (Welded) |
| UNS Number | UNS N08020 |
| DIN / W.Nr. | DIN 2.4660 |
| Common Trade Name | Carpenter 20 / Alloy 20 / AISI 20 |
| Dimensional Standard | ASME B16.9, ASME B16.28, MSS-SP-43 |
| Size Range | 1/2" to 48" (DN15 to DN1200) |
| Wall Thickness | SCH 10 / SCH 20 / SCH 40 / SCH 80 / SCH 160 / SCH XXS |
| Finish | Annealed and Pickled, Plain End, Beveled End |
| Testing | Hydrostatic, PMI, IGC, Radiography as per buyer requirement |
| Certificates | EN 10204 3.1 MTC, NABL Lab Reports, Third Party Inspection |
Alloy 20 Pipe Fittings are available in all standard configurations for buttweld and socket weld applications. Each fitting type is supplied in both WP-20 (seamless) and WP-20-W (welded) variants conforming to ASTM B366 / ASME SB366. Individual descriptions of all ten fitting types are provided below.
The Alloy 20 90 Degree LR Elbow is the most widely specified fitting in sulfuric acid piping systems. With a bend radius of 1.5D, it provides low turbulence directional changes. Available in sizes 1/2" to 48" per ASME B16.9. The niobium stabilization in UNS N08020 prevents weld zone corrosion, making these elbows reliable for long-service installations without PWHT.
The Alloy 20 45 Degree Elbow is used for gradual directional change in chemical and pharmaceutical piping. Manufactured to ASME B16.9 in both seamless (WP-20) and welded (WP-20-W) variants. Size range 1/2" to 48". Compatible with ASTM B366 specifications for corrosive media handling.
The Alloy 20 Equal Tee provides branch connections of equal diameter to the run pipe. Manufactured from UNS N08020 / DIN 2.4660 material in seamless and welded construction per ASME B16.9. Sizes from 1/2" to 48". The niobium-stabilized composition ensures no sensitization at the weld junction.
The Alloy 20 Reducing Tee allows a branch connection of smaller diameter than the run pipe. Suitable for chemical dosing systems, reactor outlets and pharmaceutical distribution lines. Available in ASTM B366 WP-20 (seamless) and WP-20-W (welded) grades per ASME B16.9 from 1/2" to 48".
The Alloy 20 Concentric Reducer is used for symmetric pipe size transitions in vertical or non-horizontal piping. Manufactured in UNS N08020 / DIN 2.4660 per ASME B16.9, available seamless and welded in SCH 10 to XXS and sizes 1/2" to 48". Preferred in sulfuric acid plant headers and reactor feed lines.
The Alloy 20 Eccentric Reducer has one flat side and is used in horizontal pipeline size reductions where draining or pump inlet alignment is required. Manufactured from Carpenter 20 / UNS N08020 material per ASME B16.9. Available in seamless (WP-20) and welded (WP-20-W) in all standard schedules.
The Alloy 20 End Cap or Alloy 20 Pipe Cap is used to seal the open end of a pipe or fitting in corrosive chemical environments. Available in ASTM B366 WP-20 and WP-20-W per ASME B16.9. Sizes 1/2" to 48". Preferred in pharmaceutical and food processing shutdown connections where no PWHT is possible.
The Alloy 20 Stub End is used with a loose backing flange assembly to allow rotation of the flange for bolt-hole alignment. Available in Long Pattern (ASME B16.9) and Short Pattern (MSS-SP-43) in sizes 1/2" to 48". UNS N08020 stub ends are widely used in sulfuric acid pump connections and heat exchanger nozzles.
The Alloy 20 Cross Fitting provides four-way pipe connections in chemical distribution and sampling manifolds. Manufactured from DIN 2.4660 / UNS N08020 per ASME B16.9 in sizes 1/2" to 24". Available in both equal and reducing cross configurations in seamless and welded construction.
The Alloy 20 3D and 5D Bends offer long-radius bending with minimal pressure drop for piping systems handling sulfuric acid and chloride media at elevated temperatures. Manufactured from ASTM B366 / ASME SB366 UNS N08020 material in sizes 1" to 24". Custom angles and radii are available on request.
The niobium-stabilized composition is the core differentiator of Alloy 20 Pipe Fittings from standard austenitic stainless steels. The addition of niobium at 8 times the carbon content stabilizes the alloy against intergranular corrosion at weld heat-affected zones. The copper content (3.0 to 4.0%) provides additional resistance to sulfuric acid attack at all concentrations and temperatures.
| Element | Min % | Max % | Key Function |
|---|---|---|---|
| Nickel (Ni) | 32.00 | 38.00 | Corrosion resistance base |
| Chromium (Cr) | 19.00 | 21.00 | Oxidizing acid resistance |
| Molybdenum (Mo) | 2.00 | 3.00 | Pitting and crevice resistance |
| Copper (Cu) | 3.00 | 4.00 | Sulfuric acid resistance |
| Niobium (Nb) | 8xC min | 1.00 max | Stabilizer, prevents IGC |
| Carbon (C) | – | 0.07 max | Kept low for weldability |
| Manganese (Mn) | – | 2.00 max | Structural |
| Silicon (Si) | – | 1.00 max | Structural |
| Sulfur (S) | – | 0.035 max | Purity control |
| Phosphorus (P) | – | 0.045 max | Purity control |
| Iron (Fe) | Balance | – | Matrix base |
| Property | Value | Standard |
|---|---|---|
| Tensile Strength | 621 MPa (90 ksi) min | ASTM B366 |
| Yield Strength (0.2%) | 241 MPa (35 ksi) min | ASTM B366 |
| Elongation | 30% min | ASTM B366 |
| Hardness (Brinell) | 217 HB max | ASTM B366 |
| Density | 8.08 g/cm³ | – |
Alloy 20 Pipe Fittings are marketed and specified under several equivalent designations across international standards. Buyers, procurement engineers and inspection agencies may use any of the following designations when specifying ASTM B366 Alloy 20 Fittings.
| UNS | DIN / W.Nr. | Trade Name | AISI | Old Name |
|---|---|---|---|---|
| N08020 | DIN 2.4660 | Carpenter 20 | AISI 20 | Alloy 20 Cb-3 |
Metinox Overseas supplies Alloy 20 Pipe Fittings from 1/2" to 48" (DN15 to DN1200) in schedules SCH 10 through SCH XXS. Representative weights for standard 90 Degree LR Elbows in SCH 40 and SCH 80 are provided below. Contact us for complete weight charts for all fitting types.
| Nominal Size | OD (mm) | SCH 40 (kg) | SCH 80 (kg) | SCH 160 (kg) |
|---|---|---|---|---|
| 1/2" | 21.3 | 0.07 | 0.09 | 0.11 |
| 1" | 33.4 | 0.18 | 0.25 | 0.38 |
| 2" | 60.3 | 0.64 | 0.91 | 1.45 |
| 4" | 114.3 | 3.18 | 4.85 | 7.26 |
| 6" | 168.3 | 9.07 | 13.6 | 20.4 |
| 8" | 219.1 | 19.5 | 29.0 | 43.1 |
| 12" | 323.9 | 59.0 | 86.2 | 127.0 |
| 16" | 406.4 | 118.0 | 172.0 | Contact us |
| 24" | 609.6 | 390.0 | Contact us | Contact us |
The most common question from procurement engineers before specifying Alloy 20 Pipe Fittings is how they compare to standard 316L stainless steel fittings. The table below addresses all critical performance parameters for buyers in sulfuric acid and chemical processing industries.
| Parameter | Alloy 20 (UNS N08020) | 316L Stainless Steel |
|---|---|---|
| Sulfuric Acid Resistance | Excellent across all concentrations | Limited, fails in hot H₂SO₄ |
| Nickel Content | 32 to 38% | 10 to 14% |
| Copper Content | 3.0 to 4.0% (acid resistance) | None |
| Stabilization | Niobium stabilized | Not stabilized |
| PWHT Required | No PWHT required | Sometimes required |
| Intergranular Corrosion | Resistant due to Nb stabilization | Susceptible at weld zones |
| Chloride Resistance | Good with high Ni + Mo | Moderate |
| Phosphoric Acid | Excellent | Poor to Moderate |
| ASTM Standard (Fittings) | ASTM B366 / ASME SB366 | ASTM A403 |
| Cost vs Performance | Higher cost, superior in acid service | Lower cost, unsuitable for H₂SO₄ |
| Recommended Service | Sulfuric acid, pharma, food, chemical | General corrosion service |
All Alloy 20 Pipe Fittings manufactured and supplied by Metinox Overseas conform to internationally recognized dimensional and quality standards. The following standards apply to our Carpenter 20 Pipe Fittings and ASTM B366 Alloy 20 Fittings range:
Alloy 20 Pipe Fittings (UNS N08020 / DIN 2.4660) are specified in industries where resistance to sulfuric acid, phosphoric acid and chloride-bearing media is critical to system integrity and personnel safety. Key application areas include:
The first use of Alloy 20 Buttweld Fittings is in sulfuric acid plants. The production of copper and nickel in UNS N08020 gives it the best resistance to sulfuric acid at any concentration, including fuming sulfuric acid (oleum). Alloy 20 Pipe Fittings are applied in the absorption towers of the acid, heat exchangers, transfer piping and pump connections in the manufacture of sulphuric acid, storage and distribution systems. Alloy 20 is also used in pickling equipment where nozzles are required in tanks, drain connections and overflow lines.
The pharmaceutical industry requires a combination of corrosion-resistant materials and non-contamination of the process streams. Alloy 20 Pipe Fittings are employed in reactor vessels, mixing tanks, transfer lines and filter housings where there is contact with acidic solvents, organic acids and halide containing media. Phosphoric acid Chemical plants that treat chlorinated solvents and nitric-sulfuric acid mixtures that require Alloy 20 Fittings that are reliable during long-life cycles of the plant.
Alloy 20 Pipe Fittings are used in food processing plants that are dealing with acidic food products, vinegar, citric acid and phosphoric acid-based cleaning systems. Synthetic fibre (rayon and nylon) manufacturing machinery that utilizes sulfuric acid spin baths is also a common user of the alloy. It is non-reactive and therefore does not contaminate food grade with any metallic elements.
Carpenter 20 Pipe Fittings are used in bleaching circuits at the pulp and paper mills because they resist the environment of chlorine dioxide, sodium hydrochlorite and sulfuric acid. Plastics manufacturing equipment that uses sulfuric acid catalysts and acidic waste streams also defines UNS N08020 fittings on pump discharge, recirculation and vent headers.
Alloy 20 Pipe Fittings Price Per Kg India depends on the fitting type, size, wall thickness, grade (WP-20 seamless or WP-20-W welded), test and certification requirements and order quantity. As raw material prices for nickel, molybdenum and niobium fluctuate in international commodity markets, Alloy 20 Pipe Fittings pricing is updated frequently.
To receive the current Alloy 20 Fittings Price India for your specific requirements, please submit your RFQ with the following details:
Payment Modes Accepted: Letter of Credit (LC), Telegraphic Transfer (TT), Cheque.
Export Destinations: UAE, Saudi Arabia, USA, UK, Singapore, South Africa, Australia and all major industrial markets.
WP-20 refers to continuous Alloy 20 Pipe Fittings that are formed without using a weld seam using hot-worked or cold-worked UNS N08020. WP-20-W refers to welded fittings prepared out of Alloy 20 plate or strip that is welded and formed. Both grades are under ASTM B366 / ASME SB366. WP-20 seamless fittings are normally used when high pressure and critical sulfuric acid service is required. In normal applications of chemical processes, the welded fittings of WP-20-W can be used as a cost-saving alternative to the same corrosion properties.
With Niobium stabilization in UNS N08020 / DIN 2.4660, formation of chromium carbides during the weld heat-affected area is prevented by nickel. The intergranular corrosion is eliminated as sensitization is not brought about during welding and hence does not require heat treatment after welding. This is a serious manufacturing benefit of Alloy 20 Pipe Fittings compared to unstabilized austenitic grades in field-welded to complex piping systems.
Yes. Alloy 20 Pipe Fittings in UNS N08020 / Carpenter 20 grade are made such that they resist dilute and concentrated sulfuric acid including the fuming sulfuric acid (oleum) at high temperatures. The copper base (3 to 4%), and the high nickel base (32 to 38%) give resistance throughout the entire range of concentration. Nevertheless, the rates of corrosion depend on operating temperature and velocity as well. Metinox Overseas advises that one should seek the services of a corrosion engineer in cases where the service conditions exceed 60 degrees Celsius.
Metinox Overseas is a supplier of Alloy 20 Pipe Fittings with a maximum of 1/2 inch (DN15) to 48 inch (DN1200) wall thickness range in all standard schedules as per ASME B16.9. Every ten suit types such as elbows, tees, reducers, caps, stub ends, crosses and bends are available. It can be custom made to special lengths and sizes not available in the standard version as well as other non-standard sizes and lengths on order with lead times being communicated during order enquiry.
Alloy 20 Pipe Fittings as well as Hastelloy C276 fittings have a great sulfuric acid resistance. Alloy 20 (UNS N08020) offers excellent resistance especially in the mid concentration range and where the chloride or phosphoric acid contamination exists. Hastelloy C276 (UNS N10276) has a wider range of resistance in reducing acids and in most cases is used in highly oxidizing environments. Alloy 20 Fittings are less expensive than Hastelloy C276, and also satisfy the needs of the majority of sulfuric acid plant and chemical process requirements. Metinox Overseas is able to provide not only alloys but also recommend on the selection of material depending on the process conditions.
Metinox Overseas is a trusted Alloy 20 Pipe Fittings supplier and manufacturer in India with a track record of supplying to sulfuric acid plants, pharmaceutical companies and chemical process industries across four continents. Our ASTM B366 Alloy 20 Fittings are supported by EN 10204 3.1 mill test certificates, PMI reports and third-party inspection from globally recognized agencies.
We supply a complete system from one source: Alloy 20 Pipes and Tubes, Alloy 20 Flanges and Alloy 20 Pipe Fittings in UNS N08020 / DIN 2.4660 / Carpenter 20, ensuring full material traceability and consistent quality across your entire piping system.
Explore our full range of Special Alloys Pipes and Tubes, Pipes and Tubes, and Flanges Manufacturer in India for your complete project material requirements.
ASTM B366 | UNS N08020 | DIN 2.4660 | WP-20 and WP-20-W | 1/2" to 48"
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