Steel pipe for gas cylinder

Gas cylinder steel pipe is used in manufacturing seamless steel gas cylinders, automotive CNG cylinders and composite cylinders. It provides excellent hot rolled thin-walled seamless steel pipe for tube-type bottle. This high-pressure gas cylinder pipe has such features: quality inside and outside surface; uniform wall thickness; light mass; high productivity and yield and low cost, etc.

Please send your inquiry by sales@sunnysteel.com

Category: Seamless pipes Tag: Seamless pipes by applications

Description

Implement specifications GB 18248, GB28884 and JIS 3429. Products are used for the manufacture of firefighting gas cylinder, industrial gas cylinder and vehicle-borne gas cylinder. Products can be ordered in accordance with the client’s requirements. It has been applied in seamless tube-type bottle bottom closing in key technology, adopting the gas cylinder pipe manufacture from punching drawing billet to thin-walled seamless steel pipe production. And this change is welcomed by users and has been an trend.

Usage	Specification No.	Steel Grade
Seamless Steel Pipe used for Gas Cylinder	GB /T18248	37Mn, 34CrMo4, 35CrMo, 30CrMnSiA, 30CrMo
Fire-fighting gas cylinders, industrial gas cylinders, vehicle gas cylinders	JIS G3429	37Mn, 34Mn2V, 30CrMo, 35CrMo, STH11, STH12, STH21, STH22, or anything else
Seamless Steel Pipe used for Gas Cylinder with Large Volume	GB/T28884	30CrMoE（4130X）, 32CrMoE（4142）
Products can be ordered in accordance with the client’s requirements.

Products can be ordered in accordance with the client’s requirements.

30CrMoE seamless tubes are used for manufacturing seamless steel tubes for gas cylinders with a capacity of 300L~3 000L.

Chemical Component of 30CrMoE

Grade		C	Si	Mn	P	S	Cr	Mo	Ni	Cu
30CrMoE	1	0.25-0.35	0.15-0.35	0.4-0.9	≤0.02	≤0.01	0.8-1.1	0.15-0.25	≤0.3	≤0.2
30CrMoE	2	0.26-0.34	0.17-0.37	0.4-0.7	≤0.02	≤0.01	0.8-1.1	0.15-0.25	≤0.3	≤0.2

*30CrMoE 1 is equal to 4130X.

Mechanical property of 30CrMoE

Standard	T.S/MPa	Y.S/MPa	E/A %	Yield Ratio	Hardness/HBW	-40℃ Impact Test/J
30CrMoE	≥720	≥485	≥20	≤86	≤269	≥32

NDT: UT 100%.

JIS G3429 Seamless tubes for high pressure gas cylinder

Chemical Compositions(%) of JIS G3429

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 of JIS G3429

Tolerance	Data
Outside diameter:	0.01
Wall thickness:	0.3
Wall thickness disparity:	Within 20% of the nominal wall thickness
Length:	>+30mm

Process

Cold drawn seamless steel tube deformed process

Cold Drawn Seamless Mechanical Tubing (CDS) is a cold drawn 1018/1026 steel tube which offers uniform tolerances, enhanced machinability and increased strength and tolerances compared to hot-rolled products. Cold drawn seamless steel tubes process Cold drawn steel tube is with hot-rolled steel coil as raw material, and tandem cold rolling pickled to remove oxide scale, its finished rolling hard roll, rolling hard volumes due to the continuous cold deformation caused by cold hardening strength, hardness increased indicators declined tough plastic, stamping performance will deteriorate, which can only be used for simple deformation of the parts. Rolling hard roll can be used as the raw material of the hot-dip galvanizing plant, hot dip galvanizing line set annealing line. Rolling hard roll weight is generally 6 to 13.5 tons, the coil diameter of 610mm.

Hot rolled seamless steel pipe deformed process

Hot-rolled seamless steel pipe production base deformation process can be summarized as three stages: perforation, extension and finishing. Hot rolled seamless steel pipe deformed process The main purpose of the perforation process is to become a solid round billet piercing hollow shell. Capillary in the specifications, accuracy and surface quality can not meet the requirements of the finished product, further improvements are needed to deform the metal through. The main purpose of the stretching machine is further reduced sectional view (main compression wall) for a larger axial extension, so that the capillary improved dimensional accuracy, surface quality and organizational performance. After stretching machine rolled steel pipe shortage collectively need further molding mill in order to achieve the requirements of the finished pipe. Rolled steel due to pass in the method widely used in the production of seamless steel tubes. So far, due to the method pass rolling steel can be divided into two categories: core pension without rolling rolling (hollow body rolling), and with the mandrel. Sizing machines, reducing mill and stretch reducing mill belonging to the hole without mandrel type continuous rolling mills are generally coffin. Its main purpose is to reduce the diameter of the deformation process or sizing get finished steel, the wall thickness of process control, can make thinning, thickening or nearly unchanged. All the traditional hole-type rolling machine with mandrel belong to extend machine. The main purpose is to reduce the deformation process perforated capillary wall thickness and outer diameter roll passes in the deformation zone and the mandrel posed, for a larger axial extension. At the same time a certain improvement in the organization, performance, accuracy, surface quality.

Cut to Length

Before cutting pipe and tubing No matter the material, measure the diameter of the pipe or tube to be cut to ensure that you use the right-size tube cutter for the job. When determining how to make a straight cut, use a tape measure and a pencil or other writing instrument to mark on the surface where you want to cut. If possible, mark around the circumference of a pipe, especially when cutting with a handsaw. Ensure that a cut is as straight as possible by securing the pipe with a vise, clamp, miter box or even duct tape to keep the length from shifting out of place while cutting. After cutting pipe and tubing

Unless a cut is perfectly clean, you should expect to remove burrs from around the edge, especially after sawing.
Use a deburring tool to clean the edge after tube cutting.
You may opt to use a metal file on the cut of a metal pipe.

Inspection

Size inspection

Geometrical inspection of steel pipes The outer diameter, wall thickness, bending and length of the steel pipe can be inspected on the inspection table with an outer caliper, a micrometer and a bending ruler, and a length tape measure.

Tolerances of pipes you should notice

Take seamless steel pipe as an example, there are some tolerances that affect quality. Noting this, and you will get a better pipe.

Weight tolerance
For pipe NPS 12 (DN300, 323.8mm) and under, the weight shall vary within -3.5% / +10%.

For pipe over NPS 12 (DN300, 323.8mm), the weight shall vary within -5% / +10%.

Pipe of NPS 4 (DN100, 114.3mm) and smaller may be weighed in convenient lots; pipe in sizes larger than NPS 4 shall be weighed separately.

Quantity tolerance
Normally mills take -10% to +10% tolerance, but TPMCSTEEL keeps ±3% variation.

Length tolerance
For Seamless pipe& tube, if definite cut lengths are ordered, the length shall vary within -0mm / +6mm.

Dimension tolerances of seamless steel pipe

Pipe types	Pipe Szie(mm)		Tolerances
Hot rolled	OD	<50	±0.50mm
	OD	≥50	±1%
	WT	<4	±12.5%
		≥4-20	+15%, -12.5%
		>20	±12.5%
Cold drawn	OD	6-10	±0.20mm
		10-30	±0.40mm
		30-50	±0.45
		>50	±1%
	WT	<1	±0.15mm
		>1-3	+ 15%, – 10%
		>3	+ 12.5%, – 10%

Standard	Hot finished seamless tube		Cold flnished seamless tube
	Out diameter (mm)	Tolerance	Out diameter (mm)	Tolerance
EN10216-1	≤100	+/-0.75% (min.+/-0.5mm)	All	+/-0.5%
EN10216-2	≤100	+/-0.75% (min.+/-0.5mm)		(min. +/-0.30mm)
DIN17175	>100	+/-0.90%		(min. +/-0.30mm)
GB/T 3087	≤460	+/-0.75% (min.+/-0.5mm)	10-30	+/-0.40mm
			>30-50	+/-0.45mm
			>50	+/-1.0%
GB/T 5310 GB/T 9948 GB/T 6479	<57	+/-0.40mm	≤30	+/-0.20mm
	57-325	+/-0.75%	>30-50	+/-0.30mm
	>325-460	+1%,-2mm	>50	+/-0.8%
ASME SA-179M ASME SA-192M ASME SA-209M ASME SA-210M ASME SA-213M JIS G 3461 JIS G 3461	≤101.6	+0.4, -0.8mm	<25.4	+/-0.10mm
			>25.4-38.1	+/-0.15mm
			>38.1-50.8	+/-0.20mm
	101.6-190.5	+0.4, -1.2mm	>50.8-63.5	+/-0.25mm
			>63.5-76.2	+/-0.30mm
			>76.2	+/-0.38mm
ASME SA106 ASME SA335	≤48.3	+/-0.40mm	≤48.3	+/-0.40mm
	48.3-114.3	+/-0.79mm
	114.4-219.1	+1.59, -0.79mm
	219.2-323.9	+2.38, -0.79mm	>48.3	+/-0.79mm
	>324	+/-1.0%	>48.3	+/-0.79mm

Tolerances on wall thickness

The wall thickness at any point shall be within the below tolerance table.

Standard	Hot finished seamless tube			Cold flnished seamless tube
DIN17175	Out diameter OD(mm)	Wall thickness T(mm)	Tolerance	Out diameter (mm)	Wall Thickness T(mm)	Tolerance
	≤130	S≤2Sn	+15%, -10%	--	All	+/-10% (min. +/-0.2mm)
		2Sn	+12.5%, -10%
		S>4Sn	+-/9%
	>130	S≤0.05da	+17.5%, -12.5%
		0.05da	+/-12.5%
		S>0.11da	+/-10%
EN 10216-1 EN 10216-2	≤219.1	-	+/-12.5% (min.+/-0.4mm)
	--	T/D≤0.025	+/-20%
		0.025	+/-15%
		0.05	+/-12.5%
		0.1	+/-10%
GB/T 3087	--	≤20	+15%,-12.5% (min.+0.45, -0.35mm)	--	1.0-3.0	+15%, -10%
GB/T 3087	--	>20	+/-12.5%	--	>3	+12.5%, -10%
GB/T 5310 GB/T 9948 GB/T 6479	--	<4.0	+15%,-10% (min.+0.48, -0.32mm)	--	2-3	+12%,-10%
		4-20	+12.5%,-10%		>3	+/-10%
		>20	+/-10%		>3	+/-10%
ASME SA-179M ASME SA-192M ASME SA-209M ASME SA-210M ASME SA-231M JIS G 3461 JIS G 3462	--	2.41-3.8	+35%, -0%	≤38.1	--	+20%,-0%
		3.8-4.6	+33%,-0%	>38.1	--	22%,-0%
		>4.6	+28%,-0%	--	--	--
ASME SA-106 ASME SA-335	--	All	+/12.5%		All	+/-10%

Note:

The size in the table above is for the hot-rolled tubes.
The size of the green area is the regular specification, we can accept orders directly, but the yellow area shall be subject to a technical evaluation.
The Out side diameter (O.D) and wall thickness (W.T.) of the tube should be complied.

PMI test

Positive material identification (PMI) testing is the examination of a material, usually a metallic alloy, to confirm the material is consistent with the user’s request.

Delivery

Steel pipe delivery status(condition)

Steel pipe delivery status(condition): cold / hard (BK), cold / soft (BKW), after cold stress relief annealing (BKS), annealing (GBK), normalized (NBK).

Condition on delivery of steel pipe

Term	Symbol	Explanation
Cold-finished/hard (cold-finished as-drawn)	BK	No heat treatment after the last cold-forming process. The tubes therefore have only low deformability.
Cold-finished/soft (lightly cold-worked)	BKW	After the last heat treatment there is a light finishing pass (cold drawing) With proper subsequent processing, the tube can be cold-formed (e.g. bent, expanded) within certain limits.
Annealed	GBK	After the final cold-forming process the tubes are annealed in a controlled atmosphere or under vacuum.
Normalized	NBK	The tubes are annealed above the upper transformation point in a controlled atmosphere or under vacuum.

The general cold strip mills, volume should go through continuous annealing (CAPL unit) to eliminate cold hardening and rolling stress, or batch annealing reach the mechanical properties of the corresponding standard specifies. Cold rolled steel surface quality, appearance, dimensional accuracy better than hot-rolled plate, and right-rolled thin product thickness is about 0.18mm, so the majority of users favor.

Cold rolled steel coil substrate products deep processing of high value-added products. Such as electro-galvanized, hot dip galvanized, electro-galvanized fingerprint resistant, painted steel roll damping composite steel, PVC laminating steel plates, etc., so that the excellent quality of these products has a beautiful, high resistance to corrosion, has been widely used.

Cold rolled steel coil finishing after annealing, cut the head, tail, trimming, flattening, smooth, heavy volume, or longitudinal clipboard. Cold-rolled products are widely used in automobile manufacturing, household electrical appliances, instruments, switches, buildings, office furniture and other industries. Steel plate strapping package weight of 3 to 5 tons. Flat sub-volume typically 3 to 10 tons / volume. Coil diameter 6m.

Packing

There are probably hundreds of different methods for packing a pipe, and most of them have merit, but there are two principles that are vital for any method to work prevent rusting and Sea transportation security.

Plastic caps plugged at the two sides of pipe ends
Should be avoided by the steel strapping and transport damage
Bundled signs should be uniform and consistent
The same bundle(batch) of steel pipe should be came from the same furnace.
The steel pipe has the same furnace number, the same steel grade, the same specifications.

Our packing can meet any needs of the customers.

Product name	Executive standard	Dimension (mm)	Steel code/ Steel grade
Black and Hot-dipped Zinc-coated Steel Pipes Seamless	ASTM A53	0.3-1200 x 1.0-150	GR.A, GR.B, GR.C
Seamless Carbon Steel for High Temperature Service	ASTM A106	10.3-1200 x 1.0-150	GR.B, GR.C
Seamless Cold-drawn Low-Carbon Steel Heat-Exchanger and Condenser Tubes	ASTM A179	10.3-426 x 1.0-36	Low Carbon Steel
Seamless Carbon Steel Boiler Tubes for High Pressure	ASTM A192	10.3-426 x 1.0-36	Low Carbon Steel
Seamless Cold-drawn Intermediate Alloy Steel Heat-exchanger and Condenser Tubes	ASTM A199	10.3-426 x 1.0-36	T5, T22
Seamless Medium-carbon Steel Boiler and Superheater Tubes	ASTM A210	10.3-426 x 1.0-36	A1, C
Seamless Ferritic and Austenitic Alloy Steel Boiler, Superheater and Heat-exchanger Tubes	ASTM A213	10.3-426 x 1.0-36	T5, T5b, T9 , T11, T22 ,T91
Seamless Carbon and Alloy Steel for Mechanical Tubing	ASTM A333	1/4"-42" x SCH20-XXS	Grade1 Gr. 3,Gr..6, Gr.8 , Gr. 9
Seamless Cold-drawn Carbon Steel Feedwater Heater Tubes	ASTM A556	10.3-426 x 1.0-36	A2, B2
Round and shaped steel cold formed welded and seamless carbon steel structural pipe.	ASTM A500	OD :10.3-820 x 0.8- 75	Grade A, B, C, D
Carbon and alloy steel mechanical tubing, either hot-finished or cold-finished	ASTM A519	10.3-426 x 1.0-36	1020, 1025, 4130, 4140
For seamless ferritic alloy-steel pipe for high-temperature service	ASTM A335	1/4"-42" x SCH20-XXS	A/SA 335 P1, P2, P11, P12, P15, P22, P91, P92, P122