ASTM A106 SEAMLESS PIPES
In this article, we illustrate ASTM A106 seamless pipes for high-temperature service (process industry): application, the chemical composition of grades A, B, and C, tolerances, mechanical properties, testing and marking requirements. At the bottom of the article, we show also a list of the main ASTM A106 pipe manufacturers.
APPLICATION OF ASTM A106 PIPES
ASTM A106/ASME SA106 pipes are seamless carbon steel pipes for high-temperature applications (up to 750 degrees F). These pipes are widely used in the oil & gas, petrochemical, power generation and shipbuilding industries, whenever the fluid to be conveyed has either high temperature or high pressure (or both combined). These pipes can be flanged, bent and formed.
ASTM A106 / SA106 pipes are available in size range from 1/2 to 28 inches, and in pipe schedules from 10 to 160 (per ASME B36.10). These pipes are available in single random length (17′ – 24′) and in double random length (36′ – 44′).
THE ASTM A106 SPECIFICATION
This specification covers carbon steel pipe for high-temperature service. These pipes are suitable for welding, bending, flanging, and similar forming operations. Mechanical testing of the specimens shall include tensile, bending, flattening, hydrostatic and nondestructive electric tests. Specimens undergoing bending tests shall consist of sections cut from a pipe. For flattening tests, the specimens shall be smooth on the ends and burr-free, except when made on crop ends. All tests shall be performed in room temperature. If any test specimen shows flaws it can be discarded and substituted for another test specimen. Before testing, if a specimen has scribe scratches, a retest shall be allowed. A retest shall also be allowed if a specimen breaks in an inside or outside surface flaw. This abstract is a brief summary of the referenced standard. It is informational only and not an official part of the standard; the full text of the standard itself must be referred to for its use and application. ASTM does not give any warranty express or implied or make any representation that the contents of this abstract are accurate, complete or up to date.
ASTM A106 PIPES CHEMICAL COMPOSITION
ASTM A106 pipes are manufactured in grades A, B, and C. NPS 1-1/2″ and below are available in the hot finished or by cold-drawn type. Pipes of NPS 2 inch and above are generally are hot rolled. ASTM A106 pipes are produced out of killed steel.
The chemical composition of the three grades of ASTM A106 is shown in the following table:
|ASTM A106 seamless carbon steel pipe – chemical composition, %|
|A106 Grade A||0.25 (1)||0.27-0.93||0.035||0.035||0.10||0.40||0.40||0.15||0.40||0.08|
|A106 Grade B||0.30 (2)||0.29-1.06||0.035||0.035||0.10||0.40||0.40||0.15||0.40||0.08|
|A106 Grade C||0.35 (2)||0.29-1.06||0.035||0.035||0.10||0.40||0.40||0.15||0.40||0.08|
ASTM A106 PIPES TOLERANCE
The manufacturing tolerances of ASTM A106 pipes are shown in the table below. To summarize:
- Diameter: see table
- Wall thickness: the minimum WT of the pipe shall not be, at any point, below the nominal pipe size minus 12.5%
- Weight: the allowed tolerance in weight shall be within -3.5% and +10% vs. specification. The weight test can be executed on lots for smaller nominal pipe sized (below 4 inches) but must be executed pipe by pipe for higher diameters (6 inch and above).
|NPS / DN||inches||mm||inches||mm|
|1/8 to 1-1/2 / DN 6 to 40||1/64 (0.015)||0.4||1/64 (0.015)||0.4|
|Over 1-1/2 to 4 / DN 40 to 100||1/32 (0.031)||0.8||1/32 (0.031)||0.8|
|Over 4 to 8 / DN 100 to 200||1/16 (0.062)||1.6||1/32 (0.031)||0.8|
|Over 8 to 18 / DN 200 to 450||3/32 (0.093)||2.4||1/32 (0.031)||0.8|
|Over 18 to 26 / DN 450 to 650||1/8 (0.125)||3.2||1/32 (0.031)||0.8|
|Over 26 to 34 / DN 650 to 859||5/32 (0.156)||4||1/32 (0.031)||0.8|
|Over 34 to 48 / DN 850 to 1200||3/16 (0.187)||4.8||1/32 (0.031)||0.8|
ASTM A106 MECHANICAL PROPERTIES
YIELD / TENSILE STRENGHT A106 PIPES
|ASTM A106 pipe||Grade A||Grade B||Grade C|
|Tensile Strength, min., psi||48,000||60,000||70,000|
|Yield Strength, min., psi||30,000||35,000||40,000|
ASTM A106 TESTING REQUIREMENTS
|NPS||test 1 pipe for each lot of|
|Tensile||<= 5″||<= 400|
|>= 6″||<= 200|
|Bending||>= 2″||<= 400|
|Flattening||2 – 5″||<= 400|
|>= 6″||<= 200|
Hydrostatic test for ASTM A106 pipes
The hydro test shall apply a pressure equal to 60% of the minimum yield strength for at least 5 seconds at atmospheric conditions. The maximum pressure shall not exceed 2500 psi for pipes up to 3 inches, and 2800 for larger sizes. If additional, non-standard, tests are executed, the pipe shall bear an “S” mark on each length or pipe bundle.
ASTM A106 PIPES MARKING REQUIREMENTS
Each length of pipe (or bundle for smaller diameters) shall have the following markings applied:
- Manufacturer name
- ASTM A106 A / B / C (material grade)
- Diameter and ANSI schedule (from 10 to 160 and XXS)
- Pipe length
- Heat number
- Hydrostatic test pressure or NDE
MANUFACTURERS OF ASTM A106 PIPES
|Jiangu Chengde Steel Tube||China|
|Mittal Steel||Czech Republic Romania|
|NKK / Tenaris||Japan|