Stainless Steel Welded Tube - Dongshang Stainless

Stainless Steel Welded Tube China Manufacturer

Stainless steel welded tube is manufactured through roll-forming strips or sheets of stainless steel into a tube shape and then welding the seam longitudinally, welded tube standards include ASTM A249, A269, A270, A312, A554 A789, and EN specifications, popular grades of stainless steel used in welded tubes include 304 and 316, which are known for their excellent corrosion resistance and high strength, other grades have 304L, 321, 36Ti and 2205 duplex. Welded tubes can be customized in terms of size and finish, including cutting and polishing services to meet specific requirements. Welded tubes are generally less expensive than seamless tubes due to the simpler manufacturing process. They are also readily available in long continuous lengths and can be produced with fast lead times.

Welded tubes can be finished in as welded, welded and drawn, polished, and bright annealed conditions, our tubes are strictly in accordance with ASTM and international standards, and all the tubes are conducted by non-destructive testing and destructive testing, these tests include eddy current and ultrasonic and pressure testing, professional manufacturing and tests are to ensure consistent weld and high quality.

Stainless Steel Welded Tube Specifications

Specifications	Tube/Pipe Type	Material	Applications
ASTM A249	Welded	Austenitic Steel	Boiler, Superheater, Heat Exchanger, And Condenser
ASTM A268	Seamless And Welded	Ferritic And Martensitic Stainless Steel	General Service
ASTM A269	Seamless And Welded	Austenitic Stainless Steel	General Service
ASTM A270	Seamless And Welded	Austenitic And Ferritic / Austenitic Stainless Steel	Sanitary Tubing
ASTM A312	Seamless, Welded, And Heavily Cold Worked	Austenitic Stainless Steel	High-Temperature And General Corrosive Service
ASTM A358	Welded	Austenitic Chromium-Nickel Stainless Steel	High-Temperature Service And General Applications
ASTM A554	Welded	Stainless Steel	Mechanical Tubing
ASTM A688	Seamless And Welded	Austenitic Stainless Steel	Feedwater Heater
ASTM A789	Seamless And Welded	Ferritic/Austenitic Stainless Steel	General Service
ASTM A790	Seamless And Welded	Ferritic/Austenitic Stainless Steel	General Service
EN 10217-7	Welded	Stainless Steel	Pressure And Corrosion Purpose
EN 10312	Welded	Stainless Steel	Water And Other Liquids

Stainless Steel Welded Tube Material

There are several types of stainless steel, Austenitic Stainless Steel, Martensitic Stainless Steel, Ferritic Stainless Steel and Duplex Stainless Steel, each type has a base grade and numerous variations, each grade has unique physical and chemical properties, and selecting the right stainless steel grade depends on the specific application.

AISI/ASTM Grades

300 series: 304, 304L, 309/309s, 310/310S, 316, 316L, 316Ti, 317L, 321
400 series: 409, 409L, 410, 420, 430, 431, 439, 440, 441, 444
Duplex stainless steel: S32750, S32760, S31803, S32205, S32304
Special Grades: 904L, 347/347H, 254SMo

EN Steel No.

1.4301, 1.4306, 1.4315, 1.4303, 1.4833, 1.4845, 1.4401, 1.4571, 1.4404, 1.4429, 1.4438, 1.4541, 1.4550, 1.4477, 1.4462, 1.4002, 1.4512, 1.4016, 1.4113, 1.4509, 1.4521, 1.4006, 1.4021, 1.4028

Welded Tube Sizes

We have a large variety of rollers, allowing us to manufacture tight tolerance tubing in a wide range of OD and wall thickness dimensions, and in various shapes including round, square, rectangular and oval.

BWG Gauge Chart
Fractional, Metric, and Imperial Sizes
Pipe Schedule
Stainless Steel Tube Weight
Stainless Steel Tubing Sizes
Welded Round Tube
Welded Square Tubing
Welded Rectangular Tubing
Welded Oval Tubing
Large Diameter
Small Diameter
.065“ stainless tubing wall thickness (1.65mm)

Welded Tube Processing

Bright Annealing Stainless Steel BA Tubing in Seamless & welded

Bright annealed
Pickling
Outer surface brushing
Inner and outer surface polishing
Inner and outer surface mirror polishing
Bead rolling or weld seam removing
Customer defined tolerances
Cut to length
U bend welded tubes
Tubes individually sleeved
Welded coil tubing

Stainless Steel Welded Tube Applications

Heat Exchanger, Boiler, Condenser

ASTM A249 stainless steel tube, covering Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes, the tubing sizes and thicknesses usually furnished to this specification are ¹/₈ in. [3.2 mm] in inside diameter to 12 in. [304.8 mm] in outside diameter and 0.015 to 0.320 in. [0.4 to 8.1 mm], inclusive, in wall thickness.
ASTM A269 stainless steel tubing, covering Seamless and Welded Austenitic Stainless Steel Tubing for General Service, the tubing sizes and thicknesses usually furnished to this specification are ¹/₄ in. [6.4 mm] in inside diameter and larger and 0.020 in. [0.51 mm] in nominal wall-thickness and heavier.
ASTM A268 stainless steel tubing, covering standard specification for a number of grades of nominal-wall-thickness, welded ferritic and martensitic stainless steel tubing for general corrosion-resisting and high-temperature service.
ASTM A789 stainless steel tubing, covering standard requirements for grades of nominal wall thickness, and stainless steel tubing for services requiring general corrosion resistance, with particular emphasis on resistance to stress corrosion cracking. These steels are susceptible to embrittlement if used for prolonged periods at elevated temperatures.

Mechanical Purpose

ASTM A554 stainless steel tubing, covering welded austenitic, ferritic, and austenitic-ferritic duplex stainless steel mechanical tubing intended for use in ornamental, structural, exhaust, and other applications where appearance, mechanical properties, or corrosion resistance is needed. As-welded or cold-reduced mechanical tubing in sizes up to 16 in. (406.4 mm) outside dimension, and in wall thicknesses 0.020 in. (0.51 mm) and over.
EN 10296-2, Welded circular steel tubes for mechanical and general engineering purposes
Exhaust pipe

Sanitary Tubing

ASTM A270 stainless steel sanitary tubing, covering grades of seamless, welded, and heavily cold-worked austenitic and ferritic/austenitic stainless steel sanitary tubing, tubes in sizes up to and including 12 in. [300 mm] in outside diameter.
EN 10357 Austenitic, austenitic-ferritic and ferritic longitudinally welded stainless steel tubes for the food and chemical industry.

Welded Tube Quality Control

In all stages from raw material to finished products, the tube is manufactured under strict quality control, making sure the tube has stable mechanical properties, excellent surface finish and high dimensional accuracy. Specialty testing services can also be provided.

Standard Testing

Tensile Strength test
Flattening test
Flare test
Flange test
Dimensional inspection
PMI
Hardness test
Eddy Current test

Optional Testing

Ultrasonic test
Hydrostatic test
Air Under Water test
Grain Size
Corrosion test
Metallographic
Radiographic test

Stainless Steel Welded Tube Manufacturing Process

Welded stainless steel tube is made from long strips or sheets, passed a rolling machine, then the strip edges are welded longitudinally and melted together, using various welding processes, making the welding beam the same as the base metal, and forming into a tube shape. The sheet width is the desired tube outside diameter, the width should be calculated before manufacturing.

TIG Welded Tube

Tungsten Inert Gas welding, another name for Gas tungsten arc welding (GTAW), is an arc welding process that uses a non-consumable tungsten electrode to produce the weld. An inert shielding gas protects the weld area and electrode from oxidation or other atmospheric contamination.

Laser Welding Tube

Laser welding, also known as Laser Beam Welding (LBW) is a fusion welding process that uses a laser beam to melt and fuse materials together. This advanced metal welding technique offers many advantages, including high precision, high speed, and the ability to weld challenging materials.

Laser welded steel pipe process: the first strip of steel is into a tube, and then the bad side of the tube is rolled out than the laser beam focal point, point diameter is also small ask gap value, and the laser beam focus is hooked in the welded tube bad side, due to the high unit density of the laser beam, and thus in the protective atmosphere whether or not to use the dry wire, can be completed at a high rate of the welding process.

Cold Drawing Stainless Steel Welded Tube

Cold-drawn steel tube is one of its different classifications according to the production process, different from the hot-rolled (expanded) tube. In the process of billet or raw material pipe expansion through a number of cold-drawing processes, Precision and surface quality are significantly better than hot rolled (expanded) tubes, but by the process constraints, its caliber and length are subject to certain restrictions.

DOM Welded Tube

DOM (Drawn Over Mandrel) is a procedure of welded tube manufacturing that uses a drawbench to pull the tube through a die and over a mandrel, allowing excellent control of the inside diameter and wall thickness.

Heat Treatment

Heat treatment is generally required after manufacture, annealing is a common heat treatment process used to eliminate steel hardening, reduce hardness, increase plasticity, improve cutting and machining properties and adjust the organizational structure. The annealing process usually involves heating the stainless steel to a certain temperature (which varies depending on the type of stainless steel), holding it and then cooling it slowly. For example, austenitic stainless steels are usually annealed at temperatures between 1040°C and 1120°C.

Stainless Steel Pipe Welding Methods

EFW Welded Pipe

EFW (Electric Fusion Welding) is a technique of welding steel pipes together by high-temperature arc heating and is a common way of fabricating chemical pipes. Unlike traditional hydro testing welding methods, EFW uses arc heating to melt the surface of the steel pipe, then rapidly cools it and applies pressure during the welding process, resulting in a seamless connection of the pipe.

ERW Welded Pipe

ERW straight seam welded pipe, also known as ‘resistance welding straight seam welded pipe’, ERW straight seam welded pipe is mainly divided into two forms ERW AC welded steel pipe and ERW DC welded steel pipe.ERW straight seam welded pipe is divided into low-frequency welding, intermediate-frequency welding, ultra-intermediate-frequency welding and high-frequency welding in accordance with the different frequencies. High-frequency welding is mainly used for the production of thin-walled steel pipe or ordinary wall thickness steel pipe, high-frequency welding is divided into contact welding and induction welding.

The process of making ERW-welded steel pipes includes a number of steps, such as longitudinal shearing, uncoiling, strip leveling, head and tail shearing, strip butt-welding, forming, welding, burr removal, sizing, flaw detection, fly-cutting, initial inspection, straightening of the steel pipe, processing of the pipe section, hydro testing, flaw detection, printing and coating, etc., which ultimately results in a finished product.

DSAW

Double Submerged arc welded, similar to other pipe manufacturing processes, the manufacture of Double Submerged Arc Welded Pipe involves first forming steel plates into cylindrical shapes. The edges of the rolled plate are formed so that V-shaped grooves are formed on the interior and exterior surfaces at the location of the seam. The pipe seam is then welded by a single pass of an arc welder on the interior and exterior surfaces.

LSAW

LSAW steel pipe (Longitudinally Submerged Arc Welding abbreviated as LSAW) is a professional expression of the term LSAW steel pipe, is a single sheet of medium-thickness plate as a raw material, the steel plate in the mold or molding machine pressed (rolled) into a pipe billet, using double-sided submerged arc welding and expanding into the production of tubes.

Welded Tube VS Seamless Tube

There are differences between welded tube and seamless tube in manufacturing, The typical appearance is that welded have welding seams, without or with additional filler metal, but seamless tube do not.

Size Range

Welded tube can be produced in a wide range of sizes and dimensions, both large diameter and small diameter, it is hard to produce very large size and very thin wall seamless tube.

Production Time

Welded tubes have a short production time, because they possess a simpler manufacturing process, in most conditions, for seamless tube, several producing processes are needed to duplicate, such as cold rolling, and heat treatment.

Working Pressures

The working pressures of the welded tube are approximately 20% less than the seamless tube, the seamless tube is a better selection for use in harsh environments.

Production Cost

Welded tube is an effective cost choice for many applications, seamless tube has a higher price, but it is also durable.

Tolerance

Welded tubes have excellent concentricity and tight tolerance in outside diameter and wall thickness.