JIS G3429 Seamless tubes for high pressure gas cylinder

JIS G3429 seamless steel tubes are used for the manufacture of seamless steel gas cylinders specified in JIS B 8230 and JIS B 8241.

.

JIS G3429 Seamless tubes for high pressure gas cylinder

Standards: JIS G3429

Size (mm):

Outer Dimensions: 19.05mm - 114.3mm
Wall Thickness:2.0mm - 14 mm
Length: max 16000mm

The main products of steel / steel grade:

JIS G3429 STH11
JIS G3429 STH12
JIS G3429 STH21
JIS G3429 STH22

Packing: Bare/bundles/crates/crate protection at the both sides of tubes or as per customers' requirements.

Painting: as requested.

Chemical Compositions(%):

Grade	C	Si	Mn	P	S	Ni	Cr	Mo
STH11	≤0.50	0.10-0.35	≤1.80	≤0.035	≤0.035	/	/	/
STH12	0.30-0.41	0.10-0.35	1.35-1.70	≤0.030	≤0.030	/	/	/
STH21	0.25-0.35	0.15-0.35	0.40 - -0.90	≤0.030	≤0.030	≤0.25	0.80-1.20	0.15-0.30
STH22	0.33-0.38	0.15-0.35	0.40 - -0.90	≤0.030	≤0.030	≤0.25	0.80-1.20	0.15-0.30

Tolerances：

Tolerance	Data
Outside diameter:	1%
Wall thickness:	+30%
Wall thickness disparity:	Within 20% of the nominal wall thickness
Length:	>+30mm

Note: the tolerance is not available for WT＜5.6mm tubes

The tubes shall be manufactured by seamless process, electric resistance welding process, or butt welding process, and those of other grades shall be manufactured by seamless process or electric resistance welding process. The tube shall be as manufactured or as cold-finished condition, or they shall be subjected to appropriate heat treatment.

The tubes shall be practically straight. and the two ends shall be at right angles to the axis of the tube.

The tubes shall be free from defects detrimental to practical use.

Seamless steel tubes for high pressure gas cylinder.

This should be marked out in the contract after negotiated by the two parties. The amount of steel tubes shorter than 4000 mm should not exceed five percent of your total number of delivered seamless steel pipe for gas cylinder. The two end surface should be perpendicular to the steel pipe axis. The cutting burrs should be took off.

Standards JIS G3429 standard is typically applicable for gas cylinder steel tubing. We can manufacture the following grade of seamless steel pipe for gas cylinder: 37Mn, 34Mn2V, 30CrMo, 35CrMo, STH11, STH12, STH21, STH22, or anything else.

Manufacturing TechnologyWe adopt hot rolling (hot expanding) or cold rolling (cold drawing) to produce gas cylinder steel replacements.
ApplicationsThis steel tube is mainly appeared to make different associated with gas cylinders, hydraulic cylinders and other high pressure cylinders. Seamless steel pipe for gas cylinder can also be applicable for Gas main Vehicle (NGV) cylinders, Compressed Natural Gas (CNG) trailers, transportation and storage of compressed hydrogen, as well as technical gases, and also scuba diving and fire extinguisher

Specifications of Seamless Steel Pipe for Gas Cylinder

Dimension Deviation

Manufacturing Method	Size Range	Allowable Outside Diameter Deviation (%)	General Class	High Class
Manufacturing Method	Size Range	Allowable Outside Diameter Deviation (%)	Allowable Wall Thickness Deviation (%)
何t Rolling (Hot Expanding)	D ＜ 339.7 mm	± 1	＋ 12.5 － 10	± 10
何t Rolling (Hot Expanding)	D ≥ 339.7 mm	± 1	＋ 15 － 12.5	＋ 12.5 － 10
Cold Rolling (Cold Drawing)	Total	± 0.75	± 10	± 7.5

Manufacturing Method	Size Range	Allowable Outside Diameter Deviation (%)	Min. Allowable Wall Thickness Deviation (%)
Manufacturing Method	Size Range	Allowable Outside Diameter Deviation (%)	General Class	High Class
何t Rolling (Hot Expanding)	D＜ 339.7 mm	± 1	＋25 0	＋22.5 0
何t Rolling (Hot Expanding)	D ≥ 339.7 mm	± 1	＋30 0	＋25 0
Cold Rolling (Cold Drawing)	Total	± 0.75	＋22.5 0	＋15 0

Advantages

JST seamless steel pipe for gas cylinder has good surface quality. There does not visible crack, wrinkling, abscission layer and rolling skin (scarring).
Inside of production process, there always exist some surface quality defects, regarding flaw, scar, laceration, rolling burr other people. We possess UNICORN ultrasonic joint inspection machine, automatic ultrasonic testing machine and magnetic flux leakage testing host. They are used for detecting obvious surface defects of gas cylinder steel tubes.
Iwowwee also employs professional inspection personnel may detect the unobvious inner and outer surface defects on the seamless steel pipe for gas tank. If find any flaw, they will be sufficient polishing, removal, repair too series of processes in keeping with relevant regulations.
Delivery StatusHot-rolled steel tubes are delivered in hot-rolled state while cold-rolled steel pipes are delivered in cold-rolled, normalizing or annealing state.

Seamless pipeSpecification, standard and identification

Seamless pipes are extensively applied for the nuclear device, gas, petrochemical, ship building and boiler industries. Seamless pipes dominates 65% of market share in Chinese boiler industry.