Pipe and Tube
Standard and Specifications
In South Africa, a large number of national and international standards for the specification of stainless steel pipe and tube are used.
The more common standards are:
ASTM A213
Standard Specification for SEAMLESS Ferritic and Austenitic Alloy-Steel Boiler, Superheater and Heat- Exchanger Tubes.
This specification covers minimum-wall thickness, seamless, ferritic and austenitic steel, boiler and superheater tubes and austenitic steel heater-exchanger tubes, designated Grades TP 304, etc.
Grades TP 304H, TP 304N, TP 316H, TP 316N, TP 321H,TP 347H and TP 348H are modifications of Grades TP 304, TP 316, TP 321,
TP 347 and TP 348 and are intended for high-temperature service such as super-heaters and reheaters.
The tubing sizes and thicknesses usually furnished to this specification are 3.2 inside diameter to 127 outside diameter and 0.38 to 12.70 wall thickness.
Mechanical property requirements do not apply to tubing smaller than 3.2 inside diameter or 0.38 thickness.
ASTM A249
Standard Specification for WELDED Austenitic Steel Boiler, Superheater, Heat-Exchanger and Condenser Tubes
This specification covers nominal-wall-thickness welded tubes made from austenitic steels with various grades intended for such as boiler, superheater, heat-exchanger or condenser tubes.
Grades TP304H, TP304N, TP316H, TP316N, TP321H, TP347H and TP348H are modifications of Grades TP304, TP316, TP321, TP347 and TP348 and are intended for high-temperature service such as super-heaters.
The tubing sizes and thickness usually furnished to this specification are 3.2 inside diameter to 127* outside diameter and 0.38 to 8.13 wall thickness.
Tubing having other dimensions may be furnished, provided such tubes comply with all other requirements of this specification.
* 18.00 outside diameter is the smallest tube manufactured by Jaguar
ASTM A268
Standard Specification for Seamless and Welded Ferritic Stainless Steel Tubing for General Service
This specification covers a number of grades of nominal-wall-thickness stainless steel tubing for general corrosion-resisting and high-temperature service. These grades are commonly known as the “straight-chromium” types and are characterised by being ferromagnetic.
Two of these grades, TP 410 and TP 429 are amendable to hardening by heat treatment, and the high chromium, ferritic alloys are sensitive to notch-brittleness on slow cooling to ordinary temperatures. These features should be recognised in the use of these materials.
Grade TP XM-8 is used primary for hot-water tank service and does not require post-weld heat treatment to prevent attack of the heat affected zone.
For tubing smaller than 12.7 in outside diameter, the elongation values given for strip specimens shall apply. Mechanical property requirements do not apply to tubing smaller than 3.2 outside diameter or with wall thinner than 0.38.
ASTM A269
Standard Specification for Seamless and Welded Austenitic Stainless Steel Tubing for General Service
This specification covers grades of nominal-wall-thickness stainless steel tubing for general corrosion-resisting and low or high-temperature service. The tubing sizes and thicknesses usually furnished to this specification are 6.4 inside diameter and larger and 0.51 nominal-wall-thickness and heavier.
Mechanical property requirements do not apply to tubing smaller than 3.2 inside diameter or 0.38 thickness.
ASTM A312
Standard Specification of Seamless and Welded Austenitic Stainless Steel Pipe
This specification covers seamless and straight-seam welded austenitic steel pipe intended for high-temperature and general corrosive service.
Note: When the impact test criterion for a low-temperature service would be 20J energy absorption or 0.38 lateral expansion some of the austenitic stainless steel grades covered by this specification are accepted by certain pressure vessels or piping codes without the necessity of conducting the actual test. For example, Grades 304, 304L and 347 are accepted by the ASME Pressure Vessel Code, Section Vlll Division 1, and by the Chemical Plant and Refinery Piping Code, ANSI B31.3 for service at temperatures as low as -250°C without qualification by impact tests. Other AISA stainless steel grades are usually accepted for service temperatures as low as -200°C withoutimpact testing. Impact testing may, under certain circumstances, be required.
For example, materials with chromium or nickel content outside the AISA ranges, and for material with carbon content exceeding 0.10% are required to be impact tested under the rules of ASME Section VIII Division 1 when service temperatures are lower than -46°C.
Grades TP 304H, TP 304N, TP316H, TP316N, TP321H, TP347H and TP348H are modifications of Grades TP 304, TP 316, TP 321,
TP 347 and TP 348 and are intended for high-temperature service.
ASTM A358/A358M – 95a
Standard Specification of Electro-Fusion Welded Austenitic Chromium-Nickel Alloy Steel Pipe for High-Temperature Service
This specification covers electric-fusion-welded austenitic chromium-nickel alloy steel pipe suitable for high temperature and general corrosive service.
Outside Diameter tolerance is ±0.5% of specified OD. Minimum wall thickness shall be <0.01 in (0.3 ) under nominal thickness.
ASTM A409/A409M – 95a
Standard Specification of Welded Large Diameter Austenitic Steel Pipe for Corrosive or High-Temperature Services
This specification covers straight seam or spiral seam electric-fusion-welded, light-wall, austenitic steel pipe intended for corrosive or high-temperature service. Sizes covered are NPS 14 to NPS 30 with extra light (Schedule 5S) and light (Schedule 10S) wall thickness. Pipe having other dimensions may be specified.
Minimum wall thickness must not be more than 0.018 in (0.46 ) under the specified thickness.
For wall thicknesses 0.188 in (4.8 ) OD tolerance is ±20%.
For wall thicknesses <0.188 in (4.8 ) OD tolerance is ±40%.
ASTM A554 – 94
Standard Specification of Welded Stainless Steel Mechanical Tubing
This specification covers welded stainless steel tubing for mechanical applications where appearance, mechanical properties, or corrosion resistance is needed.
It covers as-welded or cold-reduced mechanical tubing in sizes to 16 in. (406.4 ) outside diameter, inclusive (for round tubing) and in wall thicknesses 0.020 in. (0.51 ) and over.
Tubes shall be furnished in one of the following shapes as specified by the purchaser: round, square, rectangular, or special.
OTHER STANDARDS
Other standards for stainless steel pipe and tube which may be used are listed below:
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ASME Part II (Materials) Standard correspond in the main to the ASTM standards and are indicated SA …
e.g. ASTM A312 ASME SA312
