JIS G3461 Carbon Steel Tubes for Boiler and Heat Exchanger
JIS G3461 Carbon Steel Tubes for Boiler and Heat Exchanger
Standard:JIS G3461
Application Scope
This Japanese Industrial Standard specifies the carbon steel tubes, hereinafter referred to as the "tubes", used for exchanging heat on the inside and outside of the tube, such aswater tubes, smoke tubes, superheater tubes, air preheater tubes, etc. of the boiler, and heat exchanger tubes, condenser tubes, catalyzer tubes, etc. used in chemical and petroleum industries.
However, it is not applicable to the steel tubes for heating furnace and steel heat exchanger tubes for low temperature service.
Main grades of JIS G3461 Carbon Steel Tubes:STB 340,STB 410,STB 510
Heat Treatment
| Grade | Heat treatment | ||||
| Hot finished seamless steel tube |
Cold finished seamless steel tube
|
Electric resistance welded steel tube other than hot finished or cold finished steel tube
|
Finished electric resistance welded steel tube
|
Fold finished electric resistance welded steel tube
|
|
| STB 340 |
As manufactured, as required, low temperature annealing or normalizing may be performed.
|
Low temperature
annealing,normalizing or full annealing.
|
Normalizing |
As manufactured. However, as required, low temperature annealing or normalizing may be performed
|
Normalizing |
| STB 410 |
As manufactured. However, as required, low temperature annealing or normalizing may be performed.
|
Low temperature
annealing, normalizing
or full annealing.
|
Normalizing | Low temperature annealing | |
| STB 510 | Normalizing | ||||
Note:The cold finished electric resistance welded steel tube which has been normalized prior to cold finishing may be finished by annealing.
Chemical Composition of JIS G3461 Carbon Steel Tubes for Boiler and Heat Exchanger
| Standard | Grade | Chemical Composition Limits (%) | ||||
| C | Si | Mn | P | S | ||
| JIS G3461 | STB340 | ≤ 0.18 | ≤ 0.3 | 0.30-0.60 | ≤ 0.035 | ≤ 0.035 |
| STB410 | ≤ 0.32 | ≤ 0.35 | 0.30-0.80 | ≤ 0.035 | ≤ 0.035 | |
| STB510 | ≤ 0.25 | ≤ 0.35 | 1.00-1.50 | ≤ 0.035 | ≤ 0.035 | |
Note:Where required by the purchaser, Si may be designated as 0.10 to 0.35%.
Mechanical Properties of JIS G3461 Carbon Steel Tubes for Boiler and Heat Exchanger
Note:
(3) The tolerances on the length
Note:When an accurate length is particularly required, the tolerances shall be agreed upon by the purchaser and the manufacturer.
| Grade | Tensile Property (N/mm2) | Yield Point or Yield Strength (N/mm2) | Elongation (%) | ||
| OD ≥20 mm | 10 mm ≤OD ＜20 mm | OD ＜10 mm | |||
| NO. 11 Sample; NO. 12 Sample | NO. 11 Sample | NO. 11 Sample | |||
| Longitudinal | Transverse | Transverse | |||
| STB340 | ≥ 340 | ≥ 175 | ≥ 35 | ≥ 30 | ≥ 27 |
| STB410 | ≥ 410 | ≥ 255 | ≥ 25 | ≥ 20 | ≥ 17 |
| STB510 | ≥ 510 | ≥ 295 | ≥ 25 | ≥ 20 | ≥ 17 |
Note:
1. The above table is only applicable for heat exchanger carbon steel tubes. The buyer can appoint the upper limit value of tensile strength. The upper limit value of tensile strength is the above shown value plus 120 N/mm2.
2. For the carbon steel pipes with the thickness of less than 8 mm, we use NO.12 sample for tensile test. The minimum elongation will be reduced by 1.5% from the table value when the thickness reduces 1 mm. The value obtained will be rounded to an integer value according to JIS Z8401 (a rounding method).
Appearance of JIS G3461 Carbon Steel Tubes
(1) The tube shall be practically straight and its both ends shall be at right angles to its axis.
(2) The inside and outside surfaces of the tube shall be well-finished and free from defects injurious to use. However, in the case of electric resistance welded tube the swelling of inside surface of the weld shall be 0.25mm or less. In this case, if necessary, the purchaser may specify the inside swelling as 0.5mm or less for the tubes 50.8mm or under in outside diameter and at the same time 3.5mm or under in wall thickness.
Dimensional Tolerances The dimensional tolerances of the tube shall be as follows
(1) The tolerances on the outside diameter
Tolerances on Outside Diameter Unit: mm
| Division of outside diameter | Tolerances on outside diamete | |||
|
Hot finished seamless steel tube
|
Cold finished seamless steel tube
|
Electric resistance welded steel tube other than cold finished
|
Cold finished electric resistance welded steel tube
|
|
| Under 25 |
+0.4 -0.8 |
【0.10 | 【1.5 | 【0.10 |
| 25 or over to and excl. 40 | 【0.15 | 【0.20 | 【0.15 | |
| 40or over to and excl. 50 | 【0.20 | 【0.25 | 【0.20 | |
| 50 or over to and excl 60 | 【0.25 | 【0.30 | 【0.25 | |
| 60 or over to and excl. 80 | 【0.30 | 【0.40 | 【0.30 | |
| 80 or over to and excl. 100 | 【0.40 | +0.40 | 【0.40 | |
| -0.60 | ||||
| 100 or over to and excl.12 |
+0.4 -1.2 |
+0.40 -0.60 |
+0.40 -0.80 |
+0.40 |
| -0.60 | ||||
| 120 or over to and excl.160 |
+0.40 -0.80 |
+0.40 -1.00 |
+0.40 | |
| -0.80 | ||||
| 160 or over to and excl.200 | +0.4 | +0.40 | +0.40 | +0.40 |
| -1.8 | -1.20 | -1.20 | -1.20 | |
| 200 or over | +0.4 | +0.40 | +0.40 | +0.40 |
| -2.4 | -1.60 | -1.60 | -1.60 | |
Note
To the tolerances on the outside diameter of the electric resistance welded steel tube other than cold finished, the tolerances for the cold finished steel tube may be applied, as required by the purchaser.
(2) The Tolerances on the wall thickness and on the thickness disparity
| Tolerances |
Division of wall
thickness (mm)
|
Division of method of manufacture | Hot finished seamless steel tube | Cold finished seamless steel tube | Electric resistance welded steel tube | |||
| Division of outside diameter (mm) | Under 100 | 100 or over | Under 40 | 40 or over | Under 40 | 40 or over | ||
|
Tolerances on wall thickness %
|
Under 2 | --- | --- | +0.4mm |
+22 0 |
+0.3 |
+18 0 |
|
| 0 | 0 | |||||||
| 2 or over to and excl. 2.4 | +40 | --- |
+20 0 |
+18 0 |
||||
| 0 | ||||||||
| 2.4 or over to or excl. 3.8 | +35 | +35 | ||||||
| 0 | 0 | |||||||
| 3.8 or over to or excl. 4.6 | +33 | +33 | ||||||
| 0 | 0 | |||||||
| 4.6 or over | +28 | +28 | ||||||
| 0 | 0 | |||||||
|
Tolerances on
thickness disparity%
|
--- | Within 22.8 of wall thickness | --- | --- | ||||
Note
The term "thickness disparity" means the ratio of the difference between the maximum and the minimum of the measured wall thickness in the same section to the ordered wall thickness and this is not applicable to the tube under 5.6mm in wall thickness.
(3) The tolerances on the length
| Division | Tolerance on length | ||
|
50 mm or under in
outside diameter
|
7 m or under in length | +0.7 mm | |
| 0 | |||
| Over 7 m in length |
Add 3 mm to the plus side permissible deviation given above for each increase of 3m or its fraction in length. However, the maximum value shall be 15 mm.
|
||
|
Over 50 mm in
outside diameter
|
7 m or under in length | +10mm | |
| 0 | |||
| Over 7 m in length |
Add 3 mm to the plus side permissible deviation given above for each increase of 3m or its fraction in length. However, the maximum value shall be 15mm.
|
||
Note:When an accurate length is particularly required, the tolerances shall be agreed upon by the purchaser and the manufacturer.
W=0.02466 t (D-t)
Where
W: unit mass of tube (Kg/m)
t: wall thickness of tube (mm)
D: outside diameter of tube (mm)
Testing:
Chemical Analysis , Tensile Test , Flattening Test , Flaring Test , Reverse flattening Test ,Hydrostatic Test or Nondestructive Examination.
Marking
Each tube having passed the inspection shall be marked with the following items. However, the order of arranging the items is not specified. Further, in the case of either smaller tubs or request from the purchaser, the tubes may be bundled together and marked for each bundle by a suitable means.
(1) Class symbol
(2) Letter symbol indication the manufacturing method ()
(3) Dimensions
(4) Manufacturer's name or its abbreviation
(5) Letter symbol Z indicating the designation of special quality requirements
Note () Symbols for indicating the manufacturing method shall be as follows. However, - may be replaced by a blank.
Hot finished seamless steel tube -S –H
Cold finished seamless steel tube -S –C
Electric resistance welded steel tube other than Hot finished and cold finished -E –G
Hot finished electric resistance welded steel tube -E –H
Cold finished electric resistance welded steel tube -E -C
