What is carbon Steel (CS) :
Steel is basically a solution of carbon (C) in ferrous (FE). Carbon steel is the denomination for the steel that has almost no metallic alloy element added to it.
Carbon steel represents broad range of steel that contain
(a) 1% carbon (maxm)
(b) 1.65% manganese (maxm)
(C) 0.6% silicon (maxm)
Temperature range- it is used for temperature up to 425°c (800°f).
Types of carbon steel- generally there are 4 types of carbon steel
| NAME | CARBON CONTENT | WELDABILITY |
|---|---|---|
| Low carbon steel | 0.15 max | Excellent |
| Mild steel | 0.15 to 0.30 | Good |
| Medium carbon steel | 0.30 to 0.50 | Fair |
| High Carbon steel | 0.50 to 1 | Poor |
For each types of carbon steel piping element common ASME material standard and dimensional standard are provided below.
Carbon Steel Pipes :
Commonly used CS pipes material standard:
Seamless pipes:
| MATERIAL STANDARD | AVAILABLE IN |
|---|---|
| ASTM A 106 GR B | SEAMLESS |
| ASTM A 53 GR B | SEAMLESS & WELDED |
| API 5L GR B | SEAMLESS & WELDED |
Welded pipes:
Welded pipes are commonly manufactured in two types.
Electric resistance welded pipe (ERW)
Here no material is added during welding. Heat for weld is generated by giving –ve and +ve charge to the ends or by creating a strong electric resistance. So it’s called electric resistance welded pipe.
| MATERIAL STANDARD | DESCRIPTION |
|---|---|
| ASTM A 135 | Electric resistance welded pipe |
| IS 1239 | ERW pipe up to 6″ |
| IS3589 | ERW pipe above 6″ |
Electric Fusion welded pipe (EFW)
Here filler material is added during welding. Advanced weld process are used to accomplish the job.
| MATERIAL STANDARD | DESCRIPTION |
|---|---|
| ASTM A 134 | Electric fusion welded steel plate pipe |
| ASTM A 139 | Electric fusion welded steel plate pipe>4″NB |
Wrought fittings :
Factory made Butt welded Elbow, tees, cap, Reducer etc. comes into this category.
| MATERIAL STANDARD | DIMENSIONAL STANDARD |
|---|---|
| ASTM A 234 GR WPB/WPC | ANSI/ASME B 16.9 |
Forged Fittings :
Forges fittings like Flanges, sockolet, weldolet, Half Coupling, Forged valves comes into this category. For all of these forged fittings the material standard is one where as the dimensional standards varies
| MATERAIL STANDARD |
|---|
| ASTM A 105 |
(a). Flanges
| DIMENSIONAL STANDARD |
|---|
| ANSI/ASME B 16.5 (for flanges ≤ 24″) |
| ANSI/ASME B 16.47 (for flanges ≥24″) |
(b). Socket weld and screwed weld fittings:
Four pressure class are available for these type of fittings
| PRESSURE CLASS | APPLICABLE TO SCREWED FITTINGS | APPLICABLE PIPE SCHEDULE | APPLICABLE TO SOCKET WELD FITTINGS | APPLICABLE PIPE SCHEDULE |
| 2000# | YES | SCH 80/XS | NA | NA |
| 3000# | YES | SCH 160 | YES | SCH 80/XS |
| 6000# | YES | SCH XXS | YES | SCH 160 |
| 9000# | NA | NA | YES | SCH XXS |
| DIMENSIONAL STANDARD |
|---|
| ANSI/ASME B 16.11 |
(c). Weldolet/Sockolet
| DIMENSIONAL STANDARD |
|---|
| MSS SP 97 |
Cast Fittings :
Casted fittings like valves come into this category.
| PRESSURE TEMP. RATING LIMITATION STANDARD | ANSI/ ASME B16.34 |
| DIMENSIONAL STANDARD | ANSI/ ASME B16.10 ( for face to face dimension of flanged and bw end valves) |
| MATERIAL STANDARD | ASTM A 216 GR WCB |
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