JIS G3462 STBA23 Alloy boiler and heat exchanger tubes
 
Standard:JIS G3462
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 STBA23 alloy steel tubes with an outside diameter of 15.9 mm. to 139.8 mm.
 
 
 
JIS G3462 STBA23 Alloy boiler and heat exchanger tubes Quick Details
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, Treaded
 
 
Additional Info
Port of Shipment: Tianjin, China
Payment Terms:T / T, LC
Delivery: 7-15 days after payment
Surface: Tubes will be varnished (Outside only) to prevent rust.
Marking: Standard + Steel Grade + Size + Heat No + Lot No
Package: Bundles (hexagonal),Wooden Boxes,Crates (steel/wooden) or as required
 
 
 
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
 
 
 
Photos of JIS G3462 STBA23 Alloy boiler and heat exchanger tubes