Boiler Tube
JIS G3462 Alloy Boiler Tubes
Alloy steel tubes for boiler and heat exchanger
JIS G3462 specifies the alloy steel tubes (hereafter referred to as “tubes”) used for exchanging heat between the inside and outside of the tube, such as water tubes,smoke tubes, superheater tubes and air preheater tubes of boilers, and heat exchanger tubes, condenser tubes and catalyst tubes used in chemical and petroleum industries.
JIS G3462 STBA22 alloy steel tubes with an outside diameter of 15.9 mm. to 139.8 mm.
Manufacture:Seamless; Electric resistance welded, Cold finished ,Hot finished
Wall thickness(WT): 2.0 mm——12.7 mm.
Outer diameter (OD): 25 mm——139.8 mm
Length: 6M or specified length as required.
Ends: Plain End, Beveled End, Threaded
Manufacturing method
(1)JIS G3462 STBA22 Alloy boiler and heat exchanger tubes are manufactured by seamless process or by electric resistance welding process
(2) Plain end finishing are applied to the shape of tube end.
Heat treatment of JIS G3462 STBA22 Alloy boiler and heat exchanger tubes
| Designation of grade | Heat treatment a) |
| STBA22 | Low temperature annealing, isothermal annealing, full annealing or normalizing followed by tempering |
Notes : Low temperature annealing shall not be applied to the electric resistance welded steel tube.
Chemical Composition of JIS G3462 STBA22
| Standard:JIS G3462 | Grade | Chemical Composition Limits (%) | ||||||
| C | Si | Mn | P | S | Cr | Mo | ||
| STBA22 | ≤ 0.15 | ≤ 0.50 | 0.30-0.60 | ≤ 0.035 | ≤ 0.035 | 0.80-1.25 | 0.45-0.65 | |
Mechanical Properties of JIS G3462 STBA22
| Designa tion of grade | Tensile strength a) N/mm 2 | Yield point or proof stress N/mm 2 | Elongation % | ||||
| Outside diameter | |||||||
| Under 10 mm | 10 mm or over to and excl. 20 mm | 20 mm or over | All diameters | ||||
| Tensile test piece | |||||||
| No. 11 test piece | No. 11 test piece | No. 11 test piece or No.12 test piece | No.4 test piece | No.14A test piece | |||
| Tensile test direction | |||||||
| Pararell to tube axis | Pararell to tube axis | Pararell to tube axis | Pararell to tube axis | Pararell to tube axis | |||
| STBA22 | 410 min. | 205 min. | 22 min. | 25 min. | 30 min. | 24 min. | 21 min. |
NOTE: 1 N/mm 2 = 1 MPa
The dimensional tolerances of G3462 Alloy steel tubes for boiler and heat exchanger
Tolerances of Wall Thickness
| 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 | — | — | ||||
Tolerances of Outside Diameter
| 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 | |
Tolerances of 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. | ||
Appearance
a) The tube are practically straight, and the both ends shall be practically perpendicular to the tube axis.
b) The inside and outside surfaces of the tube are finished well without defects detrimental to use. In the case of electric resistance welded steel tube, the swelling of inside surface of the weld shall be 0.25 mm or under. The purchaser may specify the inside swelling to be 0.15 mm or less for tubes of 50.8 mm or under in outside diameter and 3.5 mm or under in wall thickness.
c) The surface of the tube may be repaired by grinding, machining or other methods,provided that the wall thickness after repairing still satisfies the specified tolerance on thickness.
d) The surface of repaired part shall be smooth along the contour of the tube.
Testings
(1)Chemical analysis
(2)Mechanical test
(3)Tensile test
(4) Flattening test
(5) Flaring test
(6)Reverse flattening test
(7)Hydraulic test or nondestructive test
Marking
The tubes which have passed the inspection shall be marked with the following items on each tube. However, the order of arranging the items is not specified.
Further, in the case of either smaller tubes or a request from the purchaser, the tubes may be bundled together and marked by a suitable method on each bundle.
Moreover, when approved by the purchaser, part of items may be omitted.
(1) Symbol of class(STBA22 )
(2) Symbol representing the method of manufacture (³)
(3) Dimensions
(4) Manufacturer’s name or its abbreviation
(5) Symbol representing the designation of special quality requirements: Z
Note ( 2 )
Symbols representing the methods of manufacture shall be as follows:
However, the sign – 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
Test report
We will submit an inspection document to the purchaser
JIS G3462 specifies the alloy steel tubes (hereafter referred to as “tubes”) used for exchanging heat between the inside and outside of the tube, such as water tubes,smoke tubes, superheater tubes and air preheater tubes of boilers, and heat exchanger tubes, condenser tubes and catalyst tubes used in chemical and petroleum industries.
JIS G3462 STBA23 alloy steel tubes with an outside diameter of 15.9 mm. to 139.8 mm.
Manufacture:Seamless; Cold finished ,Hot finished
Wall thickness(WT): 2.0 mm——12.7 mm.
Outer diameter (OD): 25 mm——139.8 mm
Length: 6M or specified length as required.
Ends: Plain End, Beveled End, Threaded
Manufacturing method
(1)The tubes of STBA23 are manufactured by seamless process.
(2) Plain end finishing are applied to the shape of tube end.
Heat treatment of JIS G3462 STBA23 Alloy boiler and heat exchanger tubes
| Designation of grade | Heat treatment a) |
| STBA23 | Isothermal annealing, full annealing or normalizing followed by tempering b) |
Notes : Low temperature annealing shall not be applied to the electric resistance welded steel tube.
The tempering temperature for JIS G3462 STBA22 Alloy steel tubes shall be 650°C or higher.
Chemical Composition of JIS G3462 STBA23
| Standard:JIS G3462 | Grade | Chemical Composition Limits (%) | ||||||
| C | Si | Mn | P | S | Cr | Mo | ||
| STBA23 | ≤ 0.15 | 0.50-1.00 | 0.30-0.60 | ≤ 0.030 | ≤ 0.030 | 1.00-1.50 | 0.45-0.65 | |
Mechanical Properties of JIS G3462 STBA23
| Designa tion of grade | Tensile strength a) N/mm 2 | Yield point or proof stress N/mm 2 | Elongation % | ||||
| Outside diameter | |||||||
| Under 10 mm | 10 mm or over to and excl. 20 mm | 20 mm or over | All diameters | ||||
| Tensile test piece | |||||||
| No. 11 test piece | No. 11 test piece | No. 11 test piece or No.12 test piece | No.4 test piece | No.14A test piece | |||
| Tensile test direction | |||||||
| Pararell to tube axis | Pararell to tube axis | Pararell to tube axis | Pararell to tube axis | Pararell to tube axis | |||
| STBA23 | 410 min. | 205 min. | 22 min. | 25 min. | 30 min. | 24 min. | 21 min. |
NOTE: 1 N/mm 2 = 1 MPa
The dimensional tolerances of G3462 Alloy steel tubes for boiler and heat exchanger
Tolerances of Wall Thickness
| 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 | — | — | ||||
Tolerances of Outside Diameter
| 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 | |
Tolerances of 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. | |
Appearance
a) The tube are practically straight, and the both ends shall be practically perpendicular to the tube axis.
b) The inside and outside surfaces of the tube are finished well without defects detrimental to use. In the case of electric resistance welded steel tube, the swelling of inside surface of the weld shall be 0.25 mm or under. The purchaser may specify the inside swelling to be 0.15 mm or less for tubes of 50.8 mm or under in outside diameter and 3.5 mm or under in wall thickness.
c) The surface of the tube may be repaired by grinding, machining or other methods,provided that the wall thickness after repairing still satisfies the specified tolerance on thickness.
d) The surface of repaired part shall be smooth along the contour of the tube.
Testings
(1)Chemical analysis
(2)Mechanical test
(3)Tensile test
(4) Flattening test
(5) Flaring test
(6)Reverse flattening test
(7)Hydraulic test or nondestructive test
Marking
The tubes which have passed the inspection shall be marked with the following items on each tube. However, the order of arranging the items is not specified.
Further, in the case of either smaller tubes or a request from the purchaser, the tubes may be bundled together and marked by a suitable method on each bundle.
Moreover, when approved by the purchaser, part of items may be omitted.
(1) Symbol of class(STBA23 )
(2) Symbol representing the method of manufacture (³)
(3) Dimensions
(4) Manufacturer’s name or its abbreviation
(5) Symbol representing the designation of special quality requirements: Z
Note ( 2 )
Symbols representing the methods of manufacture shall be as follows:
However, the sign – 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
Test report
We will submit an inspection document to the purchaser