Stainless Steel Tubes
Giriraj Impex stocks, supplies and exports stainless steel tubes – seamless and welded – to ASTM A213, A269 and A249 in grades 304/304L, 316/316L, 321, 347 and 310S. We supply stainless steel tubes from approved mills by outside diameter and wall thickness, in millimetres, inches or BWG, as straight lengths, U-bends and coils for heat exchangers, condensers, boilers and instrumentation.
Tubes differ from pipes in how they are specified. A pipe is ordered by nominal bore and schedule; a tube is ordered by its actual outside diameter and wall thickness, with closer dimensional tolerances, because it must fit into tube sheets, compression fittings and instruments.
Tube standards
| Standard | Covers | Typical use |
|---|---|---|
| ASTM A213 / ASME SA213 | Seamless ferritic and austenitic alloy steel boiler, superheater and heat-exchanger tubes | Boilers, superheaters, heat exchangers |
| ASTM A249 / ASME SA249 | Welded austenitic steel boiler, superheater, heat-exchanger and condenser tubes | Heat exchangers and condensers |
| ASTM A269 | Seamless and welded austenitic stainless steel tubing for general service | Instrumentation, hydraulic and general tubing |
| ASTM A270 | Seamless and welded austenitic stainless steel sanitary tubing | Dairy, food and pharmaceutical lines |
| ASTM A1016 | General requirements for alloy and stainless steel tubes | Tolerances and testing for A213 and A249 |
Sizes and supply forms
| Item | Details |
|---|---|
| Outside diameter | In mm or inches – fractional sizes such as ¼", ⅜", ½", ¾" and 1" for instrument and heat-exchanger tubes, and metric sizes such as 6, 10, 12, 19.05 and 25.4 mm |
| Wall thickness | In mm, inches or BWG gauge, as ordered; minimum or average wall to be stated |
| Grades | 304, 304L, 316, 316L, 321, 347, 310S; dual certified grades on request |
| Forms | Straight lengths, U-bent tubes, coiled tubing |
| Condition | Annealed and pickled, or bright annealed; polished inside and outside for sanitary tubing |
| Ends | Plain, square cut and deburred |
| Documents | Mill test certificate (MTC); third-party inspection on request |
Availability by OD and wall is confirmed with the quotation. For pipes in nominal bore sizes see stainless steel seamless pipes and stainless steel welded pipes.
Heat-exchanger and condenser tubes
Shell-and-tube heat exchangers use straight or U-bent tubes expanded or welded into tube sheets. Seamless tubes to ASTM A213 or welded tubes to ASTM A249 are used, and the tube OD, wall, length and bend radii come from the exchanger drawing. Testing typically includes a hydrostatic or eddy-current test on every tube; for U-bends, the bend area is often stress relieved or solution annealed when the specification calls for it. See heat exchanger tubes for more detail.
Instrumentation and hydraulic tubes
Instrumentation tubing carries process signals, samples and hydraulic fluid between instruments, valves and analysers, usually with compression fittings. It is normally seamless 316 or 316L to ASTM A269, fully annealed, with a bright or smooth surface and a hardness limit set by the compression fitting maker so the ferrules grip and seal reliably. Tubes are supplied in straight lengths or coils, with ends capped to keep them clean. See instrumentation tubes and capillary tubes.
Applications
Stainless steel tubes are used in heat exchangers, condensers, feedwater heaters and boilers in power and process plants; instrument and hydraulic lines in refineries, offshore platforms and chemical plants; sanitary lines in dairy, food, brewing and pharmaceutical production; and in automotive, medical and general engineering. Choose grades on the stainless steel page, and see all forms on the seamless pipes and tubes page.
Capillary and small-bore tubes are also used in medical instruments, gas chromatography and laboratory equipment, where clean, smooth bores and tight dimensions are essential.
Tubes for instrument skids are often ordered together with compression fittings and valves of the same grade.
Ordering stainless steel tubes
Bright annealed tubes are annealed in a protective atmosphere, so they keep a clean, reflective surface without pickling; they are preferred for instrumentation, hydraulic and sanitary service. Annealed and pickled tubes are standard for heat exchangers.
Please include in your enquiry:
- standard and grade (for example ASTM A269 TP316L seamless);
- outside diameter and wall thickness, stating minimum or average wall;
- length, or U-bend radii and leg lengths;
- surface condition – annealed and pickled, bright annealed or polished;
- hardness or surface roughness limits, if any;
- testing (hydrostatic, eddy current), quantity and inspection.
Other stainless steel products
Tube bundles and skids also need stainless plates for tube sheets and baffles, flanges, pipe fittings, fasteners, round bars and wires, as well as sheets, coils, circles, rings, angles, channels and flats for supports and frames.
Frequently Asked Questions
A tube is specified by its actual outside diameter and wall thickness, with tight tolerances, for heat exchangers, instruments and fittings. A pipe is specified by nominal bore and schedule to ASME B36.19M and is used to carry fluids in piping systems.
ASTM A213 covers seamless stainless and alloy steel heat-exchanger and boiler tubes, and ASTM A249 covers welded austenitic tubes. Both use ASTM A1016 for general requirements such as tolerances and testing.
Instrument tubing to ASTM A269, usually seamless 316 or 316L, fully annealed, is used with compression fittings. The hardness and surface requirements of the compression fittings in use should be stated on the order.
BWG (Birmingham Wire Gauge) is a gauge system for tube wall thickness, common for heat-exchanger tubes – for example 16 BWG or 18 BWG. Please give the wall in millimetres as well where possible.
Yes. U-bent stainless steel tubes are supplied to the bend radii and leg lengths on the exchanger drawing, with heat treatment of the bends when the specification requires it.
ASTM A213 covers seamless tubes for boilers, superheaters and heat exchangers. ASTM A269 covers seamless and welded austenitic tubing for general corrosive service and is the usual specification for instrumentation tubing.
Request a Quote for Stainless Steel Tubes
Tell us the product, grade, size, standard, quantity and delivery location, and our sales team will reply with a quotation.