Pipe ordered under this specification is used mainly for piping subjected to a temperature over 350℃。For example: transporting steam,water etc.
By a seamless process: hot finished and cold finished
Electric resistance welded
Manufacture:seamless pipe (hot finished or cold finished) / Electric resistance welded pipe
Size: O.D.: 15.0～660mm W.T.: 2～50mm
Grade:STPT370 ,STPT410,STPT480
Length: 6M or specified length as required.
Ends: Plain End, Beveled End.
Grade and Chemical Composition (％)
|
Grade |
C≤ |
Si |
Mn |
P≤ |
S≤ |
|
STPT370 |
0.25 |
0.10~0.35 |
0.30~0.90 |
0.035 |
0.035 |
|
STPT410 |
0.30 |
0.10~0.35 |
0.30~1.00 |
0.035 |
0.035 |
|
STPT480 |
0.33 |
0.10~0.35 |
0.30~1.00 |
0.035 |
0.035 |
|
Mechanical Properties |
||||||
|
Grade |
Tensile strength |
Yield strength |
Elongation % |
|||
|
N/ m㎡ |
N/ m㎡ |
No.11 or No.12 test pieces |
No. 5 test pieces |
No. 4 test piece |
||
|
Longitudinal |
Transverse |
Longitudinal |
Transverse |
|||
|
STPT370 |
370 min |
215 min |
30 min |
25 min |
28 min |
23 min |
|
STPT410 |
410 min |
245 min |
25 min |
20 min |
24 min |
19 min |
|
STPT480 |
480 min |
275 min |
25 min |
20 min |
22 min |
17 min |
| 1. The above elongation value is not applicable to tubes with outer diameter <40mm. But it must be recorded.
2. The sample meets the requirements of JIS Z2201 standard; 3. For the tube with wall thickness <8mm, when the sample No. 12 or No. 5 is used, the minimum value of the elongation is reduced by 1mm according to the wall thickness, and 1.5% is subtracted from the above value. |
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-
- Tolerance of OD and W.T
Division
Tolerance on O.D
Tolerance on W.T
Hot finished Seamless Steel Pipe
D＜50m
±0.5 mm
S＜4mm
S≥4mm
±0.5mm
±12.5%
50mm≤D＜160mm
±1%
160mm≤D＜200
±1.6 mm
D≥200mm
±0.8%
Cold finished Seamless Steel Pipe
D＜40m
±0.3 mm
S＜2mm
±0.2mm
D≥40mm
±0.8%
S≥2mm
±10%
ERW Steel Pipe D＜40m
±0.3 mm
S＜2mm
±0.2mm
D≥40mm
±0.8%
S≥2mm
±10%
For pipes of nominal size 350A or over,the tolerance on O.D maybe determined by the circumferential length. In this case,the tolerance shall be +/-0.5%
- Tolerance of OD and W.T
Hot finished seamless(ERW) steel pipe: Low temperature annealing or normalizing maybe applied
Cold finished seamless(ERW) steel pipe: low temperature annealing or normalizing
Practicality is straight, the end is cut perpendicularly, and there are no harmful defects on the inner and outer surfaces. Defects can be removed, but the minimum wall thickness must be ensured.
Grade
Manufacture method code(hot finished seamless steel pipe: S-H; Cold finished seamless steel pipe: S-C).
Dimensions(nominal diameter X nominal wall thickness or outside diameter X wall thickness).
Manufacturer’s name or its identifying brand.
Manufacture method(hot finished ERW steel pipe: E-H; Cold finished ERW steel pipe: E-C).
Dimensions(nominal diameter X nominal wall thickness or outside diameter X wall thickness).
Symbol Z to denominate the special quality requirement.
Bare pipe, black coating ( customized);
6" and below sizes In bundles with two cotton slings, other sizes in loose;
Both ends with end protectors;
Plain end, bevel end (Positive deviation is allowed, and no negative deviation is allowed)
Marking.
