JIS G3461 STB340 Carbon Steel Seamless Tubes
JIS G3461 STB 340 specifies the carbon steel 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, conde

Description

JIS G3461 STB340 Carbon Steel Tubes

JIS G3461 STB340 Carbon Steel Tubes for Boiler and Heat Exchanger

Standard: JIS G3461
Carbon Steel Tubes for Boiler and Heat Exchanger

JIS G3461 STB 340 specifies the carbon steel 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 STB340 Carbon Steel Tubes Dimensional Range & Specification
Outside Diameter：15.9mm——127mm
Wall thickness：3.4mm——12.7mm
Length：6000mm、12000m or specified length as required.
STB340 is a steel grade of JIS G3461 Standard Specification,This Japanese Industrial Standard specifies the carbon steel tubes
JIS G3461 STB340 Carbon Steel 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,JIS G3461 STB340 Carbon Steel Tubes are not applicable to the steel tubes for heating furnace and steel heat exchanger tubes for low temperature service.

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

Note:The cold finished electric resistance welded steel tube which has been normalized prior to cold finishing may be finished by annealing.

Chemical Composition

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

Note:Where required by the purchaser, Si may be designated as 0.10 to 0.35%.

Mechanical Properties

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
Appearance of JIS G3461 STB340 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.
Testing:
Chemical Analysis  , Tensile Test ,  Flattening Test  , Flaring Test  , Reverse flattening Test  ,Hydrostatic Test or Nondestructive Examination.
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)

JIS G3461 STB340 Equivalent Steel Grade

JIS G3461 ASTM ASME BS DIN ISO ABS NK LRS DNV
STB 340 A178 SA178 A 3059-P1 320 17175 st 35.8 ABS D KSTB 33 Sec 6 320 Sec 4-E-TS360