ASTM A106 seamless pressure pipe (also known as ASME SA106 pipe) is commonly used in the construction of oil and gas refineries, power plants, petrochemical plants, boilers, and ships where the piping must transport fluids and gases that exhibit higher temperatures and pressure levels.
ASTM A106 Seamless Pressure Pipe (also known as ASME SA106 pipe) covers seamless carbon steel nominal wall pipe for high-temperature service. Suitable for bending, flanging and similar forming operations.
NPS 1-1/2″ and under may be either hot finished or cold drawn. NPS 2″ and larger shall be hot finished unless otherwise specified.
Killed steel, with primary melting process being open-hearth, basic-oxygen, or electric-furnace, possibly combined with separate degassing or refining.
Steel cast in ingots or strand cast is permissible.
Hot-finished pipe need not be heat treated.
Cold-drawn pipe shall be heat treated after the final cold draw pass.
|Grade A||Grade B||Grade C|
|Carbon max. %||0.25||0.30||0.35|
|*Manganese %||0.27 to 0.93||*0.29 to 1.06||0.29 to 1.06|
|Phosphorous, max. %||0.035||0.035||0.035|
|Sulfur, max. %||0.035||0.035||0.035|
|Chrome, max. %||0.40||0.40||0.40|
|Copper, max. %||0.40||0.40||0.40|
|Molybdenum, max. %||0.15||0.15||0.15|
|Nickel, max. %||0.40||0.40||0.40|
Total of Cr, Cu, Mo, Ni, and V shall not exceed 1%
Permissible Variations in Wall Thickness
The minimum wall thickness at any point shall not be more than 12.5% under the nominal wall thickness specified.
Permissible Variations in Weights per Foot
Weight of any length shall not vary more than 10% over and 3.5% under that specified. NOTE — NPS 4 and smaller — weighed in lots. Larger sizes shall be weighed separately by length.
Outside Diameter at any point shall not vary from standard specified more than:
|NPS [DN Designator]||Over||Under|
|1/8 to 1-1/2 [6 to 40], incl||1/64 (0.015)||0.4||1/64 (0.015)||0.4|
|Over 1-1/2 to 4 [40 to 100], incl||1/32 (0.031)||0.8||1/32 (0.031)||0.8|
|Over 4 to 8 [100 to 200], incl||1/16 (0.062)||1.6||1/32 (0.031)||0.8|
|Over 8 to 18 [200 to 450], incl||3/32 (0.093)||2.4||1/32 (0.031)||0.8|
|Over 18 to 26 [450 to 650], incl||1/8 (0.125)||3.2||1/32 (0.031)||0.8|
|Over 26 to 34 [650 to 859], incl||5/32 (0.156)||4.0||1/32 (0.031)||0.8|
|Over 34 to 48 [850 to 1200], incl||3/16 (0.187)||4.8||1/32 (0.031)||0.8|
|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|
|NPS||On One Length from Each Lot of|
|Tensile||5 and smaller||400 or less|
|6 and larger||200 or less|
|Bending||2 and smaller||400 or less|
|Flattening||2 through 5||400 or less|
|6 and over||200 or less|
Inspection test pressures produce a stress in the pipe wall equal to 60% of specified minimum yield strength (SMYS) at room temperature. Maximum Pressures are not to exceed 2500 psi for NPS3 and must stay under 2800 psi for the larger sizes. Pressure is maintained for not less than 5 seconds.
Mechanical Tests Specified
Tensile Test — NPS 8 and larger — either transverse or longitudinal acceptable Smaller than NPS 8 — weighed in lots. Larger sizes — by length. Flattening Test — NPS 2-1/2 and larger. Bending Test (Cold) — NPS 2 and under.
|Degree of Bend||Diameter of Mandrel|
|For Normal A106 Uses||90||12 x nom dia. of pipe|
|For Close Coiling||180||8 x nom dia. of pipe|
Orders for material under this specification should include the following, as required, to describe the desired material adequately:
|Quantity||Feet, centimeters, or number of lengths|
|Name of material||Seamless|
|Grade||Grade A, Grade B, or Grade C|
|Manufacture||Hot-finished or cold-drawn|
|Size||NPS or Outside Diameter and Schedule Number of Average Wall Thickness|
|Special outside diameter tolerance pipe|
|Inside diameter tolerance pipe, over 10 in ID|
|Length||Specific or random|
|Test Report Required|
*ASTM A 106 grade B Seamless Pressure Pipe
B) Unless otherwise specified by the purchaser, for each reduction of 0.01 % below the specified carbon maximum, an increase of 0.06 % manganese above the specified maximum will be permitted up to a maximum of 1.65 %.
*ASME SA 106 grade B Seamless Pressure Pipe
B) for each reduction of 0.01 % below the specified carbon maximum, an increase of 0.06 % manganese above the specified maximum will be permitted up to a maximum of 1.35 %.