| Specification |
A106 NPS 1/8 -- 48 ANSI Schedules to 160 |
| Scope |
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. |
Kinds of Steel
Permitted For
For Pipe Material |
Killed Steel
Open-hearth
Electric-furnace
Basic-oxygen |
Hot-Dipped
Galvanizing |
Not covered in specification. |
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. |
Chemical
Requirements |
| |
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 |
| Phosporous, max. % |
0.025 |
0.025 |
0.025 |
| Sulfur, max. % |
0.025 |
0.025 |
0.025 |
| Silicon, min. % |
0.10 |
0.10 |
0.10 | |
Tensile
Requirements |
| Seamless |
| |
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 | |
Hydrostatic
Testing |
Inspection test pressures produce a stress in the pipe wall equal to 60% or specified minimum yield strength (SMYS) at room temperature.
Maximum Pressures are not to exceed 2500 psi for NPS 3 and under and 2800 psi for the larger sizes. Pressure is maintained for not less than 5 seconds. |
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 - by length |
Permissible
Variations in
Outside Diameter |
Outside Diameter at any point shall not vary from standard specified more than -
| NPS |
Over |
Under |
| 1 1/2 and smaller |
1/64" |
1/32" |
| 2 -- 4 |
1/32" |
1/32" |
| 5 -- 8 |
1/16" |
1/32" |
| 10 -- 18 |
3/32" |
1/32" |
| 20 -- 26 |
1/8" |
1/32" | |
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 and larger.
Bending Test(Cold) - NPS 2 and under.
For normal A106 uses:
Degree of Bend = 90
Diameter of Mandrel = 12 x nom. dia. of pipe
For close coiling:
Degree of Bend = 180
Diameter of Mandrel = 8 x nom. diameter of pipe |
Number of
Tests Required |
| |
NPS |
On One Length From Each Lot of |
| Tensile |
5 and smaller |
400 or less |
| |
6 and larger |
200 or less |
| Bonding |
2 and smaller |
400 or less |
| Flattening |
2 through 5 |
400 or less |
| |
6 and over |
200 or less |
|
| Lengths |
Lengths required shall be specified on order. No "jointers" permitted unless otherwise specified. If no definite lengths required, following practice applies:
Single Random -- 16' - 22'. 5% may be 12' - 16'
Double Random -- Minimum length 22', Minimum average 35'. 5% may be 16' - 22'. |
Required Markings
on Each Length
(On Tags attached to
each Bundle in case
of Bundled Pipe) |
Rolled Stamped or Stenciled (Mfrs. option)
• Manufacturer's name or brand.
• Length of pipe.
• A106 A, A106 B, A106 C. ANSI schedule number.
• Hydrostatic test pressure and/or NDE or NH if neither is specified
• Weight per foot (NPS 4 and larger)
• Additional "S" if tested supplementary requirements. |
General
Information |
* Unless otherwise specified, pipe furnished with plain ends.
* Purchaser may specify NDE in lieu of hydrostatic test or neither.
* Surface finish standards are outlined in specification. |