Sulfuric Acid Plant Lines
Sulfuric acid plants pipe the connections to their acid coolers and heat exchangers in this alloy, with each run ordered by NPS and schedule and supplied stabilized-annealed for spool fabrication.
ASTM B729 / UNS N08020 / W.Nr. 2.4660
Nickel Alloy 20 Seamless Pipes Manufacturer in Thailand
Produced to ASTM B729 at our Ban Bueng, Chonburi mill, Nickel Alloy 20 seamless pipes from Thaida Stainless Steel Manufacturing (Thailand) Co., Ltd. are made in UNS N08020 (W.Nr. 2.4660), a niobium-stabilized nickel-iron-chromium-molybdenum-copper alloy for sulfuric acid piping. In our nickel alloy seamless pipes range it is one of three iron-bearing nickel alloys offered beside commercially pure nickel. Every length leaves the mill stabilized-annealed, and quotations, order entry and certificates are handled by our office in Bang Phli, Samut Prakan.
Nickel Alloy 20 seamless pipeUNS N08020 / W.Nr. 2.4660
- 6 to 457 mmOutside diameter
- 1 to 65 mmWall thickness
- Up to 18 mLength
- EN 10204 3.1Test certificate
EN 10204 3.1 certificate / 3.2 on request
Specifications of ASTM B729 Alloy 20 Seamless Pipes
Each item on an order for this grade is written as NPS and schedule, with the end preparation and length beside it. The table lists the range we quote and the condition, tests and certificate that come with every length.
- Standard
- ASTM B729
- Grade
- Alloy 20 (UNS N08020)
- Outside Diameter
- 6 to 457 mm
- Wall Thickness
- 1 to 65 mm
- Length
- Up to 18 mcut to length or random
- Ordering Basis
- Standard pipe size (NPS) and schedule
- Manufacturing Route
- 1Seamless
- 2Pierced from solid billet and cold drawn
- Delivery Condition
- Stabilized-annealed
- Ends
- Plain, cut and deburred; beveled for welding, or threaded on heavier schedules, when the order gives the details
- Testing
- Chemical analysis and tension test per lot
- Hydrostatic or nondestructive electric test on each piece
- Certification
- Manufacturer's certification and test report with every order
- Test Certificate
- EN 10204 3.13.2 on request
ASTM B729, titled "Standard Specification for Seamless Nickel-Iron-Chromium-Molybdenum-Copper Nickel Alloy Pipe and Tube", covers UNS N08020 and two other alloys as seamless pipe and tube intended for general corrosive service. It identifies the alloy by its UNS number only, so UNS N08020 is the designation in the marking and on the certificate, with Alloy 20 kept as the commercial name. The standard admits cold-worked and hot-finished product; our pipe is pierced from solid billet and cold drawn to size. Pipe is ordered by standard pipe size and schedule, while Nickel Alloy 20 seamless tubes come under the same standard but are ordered by outside diameter and average or minimum wall.
Chemical analysis and a tension test are made once per lot. Each ASTM B729 Alloy 20 seamless pipe in the lot then passes either a hydrostatic test or a nondestructive electric test, eddy current or ultrasonic. ASTM B729 makes a manufacturer's certification, together with a report of the test results, mandatory on every order, and we issue both as an EN 10204 3.1 (3.2 on request) material test certificate. Tests you wish to witness at our mill are named on the purchase order, and independent third-party inspection is available on request.
UNS N08020 Seamless Pipe Chemical Composition
ASTM B729 sets maximums for carbon, manganese, phosphorus, sulfur and silicon and ranges for nickel, chromium, molybdenum and copper, with iron as the remainder, determined by difference. Niobium plus tantalum is the one limit written against another element: at least eight times the carbon content, with 1.00% as the ceiling.
- FeIron, Remainder (by difference)
- NiNickel, 32.00 to 38.00
- CrChromium, 19.00 to 21.00
- NbNb + Ta (Niobium plus Tantalum), 8 x C min, 1.00 max
- CuCopper, 3.00 to 4.00
UNS N0802020
| Element | Limit per ASTM B729 (%) |
|---|---|
| C (Carbon) | 0.07 max |
| Mn (Manganese) | 2.00 max |
| P (Phosphorus) | 0.045 max |
| S (Sulfur) | 0.035 max |
| Si (Silicon) | 1.00 max |
| Ni (Nickel) | 32.00 to 38.00 |
| Cr (Chromium) | 19.00 to 21.00 |
| Mo (Molybdenum) | 2.00 to 3.00 |
| Cu (Copper) | 3.00 to 4.00 |
| Nb + Ta (Niobium plus Tantalum) | 8 x C min, 1.00 max |
| Fe (Iron) | Remainder (by difference) |
The lot chemical analysis reported on the certificate for each UNS N08020 seamless pipe is read against these limits.
Mechanical Properties of Seamless Nickel Alloy 20 Pipe
Table 2 of ASTM B729 prints a single row of minimums for this alloy, with no split by condition or outside diameter, so the same figures apply to every NPS and schedule of seamless nickel alloy 20 pipe.
| Property | Minimum |
|---|---|
| Tensile strength | 80 ksi (550 MPa) |
| Yield strength (0.2% offset) | 35 ksi (240 MPa) |
| Elongation in 2 in. (50.8 mm) or 4D | 30.0% |
The ksi figures are the requirement, and the MPa values are conversions given for information only. The lot tension result on the certificate is read against this one row, whatever the size of the line.
Stabilized-Annealed Seamless Alloy 20 Pipe
ASTM B729 requires UNS N08020 product to be furnished in the stabilized-annealed condition. A note in the standard recommends annealing at 1800 to 1850°F (982 to 1010°C), followed by quenching in water or rapid cooling by other means; that range is a recommendation of ASTM B729, while the stabilized-annealed condition itself is the requirement.
Stabilization comes from the niobium (columbium) plus tantalum addition, held at no less than eight times the carbon content. Niobium combines with carbon, which limits the chromium carbide that forms at grain boundaries when seamless Alloy 20 pipe is cut and welded into spools during fabrication.
Equivalent Designations of Alloy 20
Alloy 20 appears on drawings under its commercial name, its UNS number and its European material number. ASTM B729 lists the alloy by UNS number; the W.Nr. entry is a cross-reference for reading a European callout and makes no statement of conformance to a European standard.
- Commercial nameAlloy 20, also written Nickel Alloy 20
- ASTM B729 (USA)UNS N08020
- Europe (W.Nr.)2.4660
A drawing that calls for seamless WNR 2.4660 pipe is entered as UNS N08020, the designation our certificate reports.
Seamless WNR 2.4660 Pipe Sizes and Tolerances
We quote seamless WNR 2.4660 pipe from 6 mm to 457 mm OD with walls from 1 mm to 65 mm, in lengths up to 18 m, cut to length or random. Each item is ordered as standard pipe size and schedule. Schedule walls are nominal walls, so pipe is read against the nominal-wall column below; the minimum-wall column covers product ordered to a specified minimum wall, the route ASTM B729 gives for tube.
Nickel Alloy 20 seamless pipes are measured against the permitted variations that apply to ASTM B729 cold-worked pipe:
| Nominal OD, mm (in.) | OD Tolerance (mm) | Nominal Wall | Minimum Wall |
|---|---|---|---|
| Up to 10 (0.400), incl. | ±0.10 | ±15.0% | +30% / 0 |
| Over 10 to 16 (5/8), excl. | ±0.13 | ±15.0% | +30% / 0 |
| 16 (5/8) to 38 (1 1/2), incl. | ±0.19 | ±10.0% | +22% / 0 |
| Over 38 to 76 (3), incl. | ±0.25 | ±10.0% | +22% / 0 |
| Over 76 to 114 (4 1/2), incl. | ±0.38 | ±10.0% | +22% / 0 |
| Over 114 to 152 (6), incl. | ±0.51 | ±12.5% | +28% / 0 |
| Over 152 to 168 (6 5/8), incl. | ±0.64 | ±12.5% | +28% / 0 |
| Over 168 to 219 (8 5/8), incl. | ±0.79 | ±12.5% | +28% / 0 |
| Over 219 to 356 (14), incl. | +1.57 / -0.79 | +15.0% / -12.5% | +30.0% / 0 |
| Over 356 to 610 (24), incl. | +3.18 / -0.79 | +15.0% / -12.5% | +30.0% / 0 |
Swipe sideways to see the full table.
Each limit applies to individual measurements, including ovality and eccentricity, with two exceptions. On thin-wall pipe, with wall 3% of OD or less, the mean OD must meet the table and single readings may exceed it by 0.5% of the nominal OD. On pipe over 114 mm OD with wall above 3% of OD, the mean OD meets the table and single readings may reach twice the table value. Our range ends at 457 mm OD, inside the last band.
| OD (mm) | Cut Length Tolerance (mm) |
|---|---|
| Under 50.8 | +3.2 / 0 |
| 50.8 and over | +4.8 / 0 |
These length limits apply to cut lengths up to 7.3 m. Longer cut lengths take an extra 3.2 mm for each 3 m or part of it, up to 12.7 mm more, and random lengths with their variation are agreed on the order.
Seamless 2.4660 Alloy Pipe Compared with Related Grades
Seamless 2.4660 alloy pipe and Alloy 31 seamless pipes are both made from iron-bearing nickel alloys, but to different standards and with differently balanced analyses. Alloy 31, to ASTM B622, holds carbon to 0.015% max and carries 6.0 to 7.0% molybdenum, 26.0 to 28.0% chromium and 0.15 to 0.25% nitrogen, with copper at 1.0 to 1.4%. Alloy 20 puts more weight on copper, at 3.00 to 4.00%, carries 2.00 to 3.00% molybdenum and is niobium-stabilized, with carbon up to 0.07%. For process lines that do not call for a copper-bearing nickel alloy, stainless steel 316L seamless pipes are the lower-alloy route, made to their own stainless steel pipe standard.
Industrial Applications of Seamless N08020 Pipe
Seamless N08020 pipe carries sulfuric acid, mixed acids and other corrosive process streams in chemical, petrochemical, fertilizer and power plants, chosen for its resistance to sulfuric acid and to pitting and crevice attack.
Pickling and Metal Cleaning Lines
Steel pickling and metal cleaning plants use the pipe for acid transfer runs and bath overflow piping, lines that stay in contact with the pickling solution throughout each production shift.
Corrosive Chemical Transfer
Chemical plants move harmful and corrosive chemicals between storage and process units through this pipe, with beveled ends specified wherever the line class calls for butt-welded joints.
Synthetic Fiber Acid Recovery
Synthetic fiber and plastics producers route their acid recovery streams through seamless nickel alloy 20 pipe, and the same plants use it for the spinning-bath circuits that serve their heat exchangers.
Flue Gas Desulfurization Piping
Power stations install seamless 2.4660 alloy pipe in their flue gas desulfurization systems, selecting NPS and schedule circuit by circuit, with every length traceable to its certificate by heat number.
Fertilizer and Pharmaceutical Acid Lines
Fertilizer plants run their process piping in the alloy, and pharmaceutical plants use it for transfer lines in process steps that handle sulfuric acid, each line documented to ASTM B729.
Shipping and Packaging of Seamless 2.4660 Pipe
Packing
Full lengths in strapped bundles, small-bore and cut pieces in wooden cases, with end protectors fitted to every piece.
Marking
Each pipe of 19.0 mm OD and larger and longer than 914 mm carries the manufacturer's name or brand, UNS N08020, the letters ASTM with the specification number B729, the heat number and the nominal size; smaller or shorter pipe is marked on each piece or on a tag fixed to the bundle or box.
Documents
EN 10204 3.1 (3.2 on request) certificate with the ASTM B729 test report, plus a packing list for each bundle or case.
Terms
FOB, CIF or CFR, with the port of loading named in the offer.
Timing
Production slot and dispatch date confirmed on the order acknowledgment.
Seamless Alloy 2.4660 Pipe Price per kg
Seamless Alloy 20 pipe is indicatively priced at USD 20 to 40 per kg. The nickel market moves a quote most, with molybdenum and copper behind it. Light schedules and small NPS need more cold-drawing and annealing work for each kilogram than heavy sections, while cut lengths, short runs or extra inspection push the figure toward the upper end. Send your size list and quantities for a firm price.
Indicative price, Nickel Alloy 20 Seamless Pipes
USD 20 to 40 per kg
Indicative only. Send your sizes and specification to Thaida for a firm quotation.
- Outside diameter
- Schedule
- Length
- Quantity
- Testing and certification
- Nickel price
- Molybdenum price
- Copper price
Production and Sales Addresses
Nickel Alloy 20 seamless pipes are produced at 154 Moo.1 Map Phai, Ban Bueng, Chonburi 20170, Thailand. Quotations and shipping documents are prepared at our office, 89/18 Moo.15 Enterprize Park, Bangna-Trad Road, Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand. We supply projects across Thailand and export to Singapore, Malaysia, Vietnam, Indonesia, the Philippines and India.
Factory154 Moo.1 Map Phai, Ban Bueng,
Chonburi 20170, Thailand
Chonburi 20170, Thailand
Office89/18 Moo.15 Enterprize Park, Bangna-Trad Road,
Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand
Bang Kaeo, Bang Phli, Samut Prakan 10540, Thailand
Exporting to
- Singapore
- Malaysia
- Vietnam
- Indonesia
- Philippines
- India
Nickel Alloy 20 Seamless Pipe FAQ
What does an order under ASTM B729 need to state?
The alloy or UNS number, the ASTM designation and year of issue, the finish, standard pipe size and schedule, length as cut or random, and quantity in feet or number of pieces. Add the test type if you wish to fix it, any non-standard test pressure, the end preparation and any tests you wish to witness.
Does the stabilized-annealed condition have to be written on the order?
No. ASTM B729 requires UNS N08020 to be furnished stabilized-annealed, so the condition is not an order choice; the same standard sets solution-annealed and annealed conditions only for its other two alloys. Your order states the finish, and the certificate confirms that the pipe meets ASTM B729, which includes the stabilized-annealed condition.
Is Alloy 20 suited to sulfuric acid piping?
Yes, sulfuric acid is the duty the grade is known for. Its 3.00 to 4.00% copper gives the resistance to sulfuric acid, while 2.00 to 3.00% molybdenum adds resistance to pitting and crevice attack, and ASTM B729 covers the pipe for general corrosive service. Send the acid concentration, temperature and any chloride content with your line list.
How are the pipe ends prepared for welding?
Plain ends, cut and deburred, are furnished unless the order gives other details. For a butt-welded line, state the bevel on each item and we prepare the ends to it; threaded ends are supplied on heavier schedules when the thread is specified. One order can mix plain and beveled pieces, so give the end type item by item.
Who decides between the hydrostatic and the electric test?
The manufacturer, unless your purchase order names the test. The hydrostatic test applies 1000 psi (6.9 MPa), or less where the allowable fiber stress limits it, with the full length examined for leaks under pressure. A leaking pipe is rejected, though leaking areas may be cut out and the pipe retested. The electric test is eddy current or ultrasonic.
What does the ASTM B729 certificate confirm?
That the pipe was manufactured, tested and inspected to ASTM B729 and that test results on representative samples meet its requirements, with a report of the results: lot chemical analysis, lot tension test and the hydrostatic or electric test on each piece. We issue it as EN 10204 3.1 (3.2 on request), matching the heat number in the marking.
How do I choose between Alloy 20 and Alloy 31 for a pipe line?
Let the line class and the medium decide. Alloy 20 is made to ASTM B729, which makes certification mandatory and sets one strength row of 80 ksi (550 MPa) tensile. Alloy 31 is made to ASTM B622, with a higher tensile minimum of 94 ksi (650 MPa) and certification when specified. Send both, and we confirm the grade.
Who carries out a product check analysis on Alloy 20?
The purchaser, if one is wanted. ASTM B729 makes product (check) analysis wholly the purchaser's responsibility, and the order should state whether samples for it are to be furnished. The heat number in the marking ties every sample to its certificate.
Request a Quote for Nickel Alloy 20 Seamless Pipes
or email sales@thaida.co.th