JIS G3461 STB 340 Boiler and Heat Exchanger Tubes
 
Standard: JIS G3461
Carbon Steel Tubes for Boiler and Heat Exchanger
 
 
JIS G3461 STB 340 specifies the carbon steel tubes, hereinafter referred to as the "tubes", used for exchanging heat on the inside and outside of the tube, such as water 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.
 
 
 
JIS G3461 STB 340 Boiler and Heat Exchanger Tubes Quick Details
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, 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
 
 
 
 
Method of manufacture
Seamless; Electric resistance welded, Cold finished ,Hot finished
 
Heat Treatment of JIS G3461 STB 410
 

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

 
 
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 STB 340

Standard	Grade	Chemical Composition Limits (%)
		C	Si	Mn	P	S
JIS G3461	STB 340	≤ 0.18	≤ 0.3	0.30-0.60	≤ 0.035	≤ 0.035

 
Mechanical Properties of JIS G3461 STB 340
 

Grade	Tensile Property (N/mm2)	Yield Point or Yield Strength (N/mm2)	Rockwell hardness HRB	Elongation (%)
				OD ≥20 mm	10 mm ≤OD ＜20 mm	OD ＜10 mm
				Longitudinal	Transverse	Transverse
STB 340	≥ 340	≥ 175	77 max.	≥ 35	≥ 30	≥ 27

 
 
Note: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.
 
 
 
 
The dimensional tolerances of .JIS G3461 Carbon 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
（1）The tube are practically straight and its both ends shall be at right angles to its axis.
（2）The inside and outside surfaces of the tube are well-finished and free from defects injurious to use.
 
 
 
Testings
(1)Chemical Analysis
(2)Tensile Test
(3)Flattening Test
(4) Flaring Test
(5) Reverse flattening Test
(6)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(STB 340)
(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
 
 
Report
We will, in general, submit to the purchaser a detailed statement of the test results, method of manufacture, ordered dimensions, quantity, work number indicating the history of manufacture, etc.
 
 
 
Photos of JIS G3461 STB 340 Boiler and Heat Exchanger Tubes