What does resistance do in an electric circuit?
resistance, in electricity, property of an electric circuit or part of a circuit that transforms electric energy into heat energy in opposing electric current. Resistance involves collisions of the current-carrying charged particles with fixed particles that make up the structure of the conductors.
How to wire for an electric welder?
The Key to Wiring a 230 Volt Welder is the Specified Receptacle
- Most 230 volt welders come with a cord and receptacle.
- The receptacle and cord are rated for a specified amperage rating and this should be the size of the electrical circuit, which should be indicated in the owners manual.
- The size of the electrical circuit wiring must be withing the rating of the welder cord and plug, or as specified in the manual.
Does bend in the wire effect the electric resistance?
Small bends in a wire do not affect on its length and area of cross-section. So there will be no change in electrical resistance.
What is electric resistance?
What is Electrical Resistance? Resistance (also known as ohmic resistance or electrical resistance) is a measure of the opposition to current flow in an electrical circuit. Resistance is measured in ohms, symbolized by the Greek letter omega (Ω). The larger resistance, the greater the barrier against the flow of current.
What is meant by electric resistance welding?
Resistance welding, sometimes called electric resistance welding (ERW),is a process by which metals can be joined together by applying pressure and conducting a strong electric current through the metal combination to heat up the welding joint and melt the metals, forging them together.
What is electric welded pipe?
ERW pipe is manufactured by cold forming a flat steel strip into a rounded tube and passing it through a series of forming rollers to obtain a longitudinal seam. The two edges are then simultaneously heated with a high frequency current and squeezed together to produce a bond.
What is ERW pipe used for?
ERW steel pipes are manufactured by low-frequency or high-frequency resistance "resistance". They are round pipes welded from steel plates with longitudinal welds. It is used to transport oil, natural gas and other vapor-liquid objects, and can meet various requirements of high and low pressure.
What is ERW pipe specification?
ERW Standard and Line Pipe GradesGrade A Carbon Steel(ASTM A53, A523, API 5L PSL1 )Minimum Yield Strength:30,000 psiMaximum Yield Strength:NoneMinimum Tensile Strength:48,000 psiNotes: This grade may be used for standard pipe, line pipe, or conduit pipeas specified in the various ASTM and API specifications.
How is ERW made?
Electric resistance welded (ERW) pipe is manufactured by cold-forming a sheet of steel into a cylindrical shape. Current is then passed between the two edges of the steel to heat the steel to a point at which the edges are forced together to form a bond without the use of welding filler material.
What is ERW and HFW?
ERW have low, medium, high frequency welding processes, and HFW is specially for high-frequency electric resistance welding. The differences between ERW and HFW steel pipe, is EFW is a type of ERW process for ordinary and thin-wall thickness steel pipes.
What is difference between seamless and ERW pipe?
Seamless pipe is manufactured by extruding the metal to the desired length; therefore ERW pipe have a welded joint in its cross-section, while seamless pipe does not have any joint in its cross-section through-out its length.
Which is better seamless or ERW pipe?
Seamless steel pipe has better pressure capacity, strength is higher than ERW welded steel pipe. So it is widely applied in high pressure equipment, and thermal, boiler industries. Generally the welding seam of the welded steel pipe is the weak point, the quality affect overall performance.
Where are ERW tubes used?
ERW tubes are used for engineering purposes, fencing, scaffolding, automobile sector, water and gas conveyance, agriculture, etc.
What is the difference between seamless and welded pipe?
Seamless tube is extruded and drawn from a billet while welded tube is produced from a strip that is roll formed and welded to produce a tube. Welded tube is considerably less expensive than seamless tube and is readily available in long continuous lengths.
Is ERW tube seamless?
Most or all pipes in the piping industry are produced seamlessly or through the welding/Erw process. The main difference between seamless and erw pipe is that a seamless pipe is produced without the help of welds or seams, however, erw pipes are manufactured by welding pieces of steel longitudinally.
Which is better seamless or ERW pipe?
Seamless steel pipe has better pressure capacity, strength is higher than ERW welded steel pipe. So it is widely applied in high pressure equipment, and thermal, boiler industries. Generally the welding seam of the welded steel pipe is the weak point, the quality affect overall performance.
What is difference between seamless and ERW pipe?
Seamless pipe is manufactured by extruding the metal to the desired length; therefore ERW pipe have a welded joint in its cross-section, while seamless pipe does not have any joint in its cross-section through-out its length.
What is the difference between ERW and Saw pipes?
Although the overall performance of both ERW pipe and SAW pipe are the same,when the pipe becomes defective,the steel scrap and welding can be done on ERW pipe,while it is not the same in case of SAW,which would result in cracking or corrosion.So ERW pipe are more durable than SAW pipe.
What is the difference between seamless pipe and welded pipe?
Seamless tube is extruded and drawn from a billet while welded tube is produced from a strip that is roll formed and welded to produce a tube. Welded tube is considerably less expensive than seamless tube and is readily available in long continuous lengths.
What is ERW pipe?
An electric resistance welded (ERW) pipe is one of the most versatile tools in the industry. However, ERW pipes are only one of the numerous types of pipe available. It is important to know the differences between each type of pipe so that the right pipe can be chosen. Rolled and welded pipe is made from sections of steel plate, rolled into cans.
How is ERW pipe made?
In contrast, an ERW pipe is made by rolling metal and then heating the two edges with electricity so they form a weld down its length. This forms a “seam,” differentiating it from a seamless pipe. A few advantages to note with ERW pipe: There are no fusion metals used during the manufacturing process.
How thick is a spiralweld pipe?
Rolled and welded pipe can be made in diameters of up to 16 feet and over 2.0 inches in thickness. Spiralweld pipe, like ERW pipe, is also manufactured from steel coil.
Can you see a weld seam in a fusion welding?
There are no fusion metals used during the manufacturing process. This means that the pipe is extremely strong and durable. The weld seam cannot be seen or felt. This is a major difference when looking at the double submerged arc welding process, which creates an obvious welded bead that might need to be eliminated.
What is ERW welding?
Several electric resistance welding (ERW) processes are available for tube and pipe production. While each process has different characteristics, all ERW processes have one thing in common–all of them produce a forged weld.
What is the heat generated by weld power?
As the name implies, the heat generated by the weld power is a result of the material's resistance to the flow of electrical current. The pressure comes from rolls that squeeze the tube into its finished shape.
What is contact wheel welding?
In rotary contact wheel welding, the electrical current is transmitted through a contact wheel at the weld point. The contact wheel also applies some of the forge pressure necessary for the welding process. The three main types of rotary contact wheel welders are AC, DC, and square wave.
What are the two types of welding machines?
HF welding machines also are classified by how they generate power. The two types are vacuum tube and solid-state. The vacuum tube type is the traditional power supply. Since their introduction in the early '90s, however, solid-state units have quickly gained prominence in the industry.
How is a forged weld created?
A forged weld is created by applying a combination of heat and pressure, or forging force, to the weld zone . A successful forged weld uses the optimum amount of heat, which is normally slightly less than the melting point of the material, and a nearly simultaneous application of circumferential pressure to the section, which forces the heated edges together (see Figure 1 ).
What are the two processes used in HF welding?
Processes. The two HF welding processes are HF contact and HF induction. In both processes, the equipment that provides the electrical current is independent from the equipment that supplies the forge pressure. Also, both HF methods can employ impeders, which are soft magnetic components located inside the tube that help to focus the weld current in the strip edges.
What are the two main types of ERW?
The two main types of ERW are high-frequency (HF) and rotary contact wheel.
Erw Pipe Production Process
- The following is the general process of making electric resistance welded pipes by Wanzhi Steel for your reference. Raw material → coiling → uncoiling → clamping and leveling → shearing and butt welding→ horizontal spiral bushing → disc shearing → rough forming and fine forming → induction welding → internal and external burr elimination → intermed...
Storage Methods For Erw Pipes
- 1. Storage by Specification
Packaged electric resistance welded pipes should be stacked by specification and placed neatly to avoid confusion. Storing by specification will not confuse and is easy to identify. - 2. Reasonable Stacking
When stacking electric resistance welded pipes, remember not to stack them too high, generally, five layers are appropriate. In addition, there should be a pedestrian passage between the piles to facilitate workers to walk.
Finished Product Delivery – Wanzhi Steel
- 1. About Delivery Time
Wanzhi Steel will ship the products within the mutually agreed time to avoid the delay of your project. In addition, our factory has a large stock of ERW pipe, so if you need resistance welded pipe urgently, we can meet your demand. - 2. About the Quality
Before shipment, Wanzhi Steel will conduct strict quality inspections on the finished products. Our factory is equipped with advanced testing equipment, and only after passing the test will the electric resistance welded pipe be shipped out. In addition, we also accept third-party testing to …
Conclusion
- Wanzhi Steel has a complete range of welded pipes, including ERW pipes, LSAW pipes, SSAW pipes, and so on. We have been in the steel industry for 17 years and can provide quality steel pipe products to customers all over the world. If you order our products in large quantity, you will also enjoy factory sales price. Contact us now to get the latest quote.
Overview
Electric resistance welding (ERW) is a welding process where metal parts in contact are permanently joined by heating them with an electric current, melting the metal at the joint. Electric resistance welding is widely used, for example, in manufacture of steel pipe and in assembly of bodies for automobiles. The electric current can be supplied to electrodes that also apply clamping pressure, or may be induced by an external magnetic field. The electric resistance wel…
Low-frequency Electric resistance welding
Low-frequency electric resistance welding, LF-ERW, is an obsolete method of welding seams in oil and gas pipelines. It was phased out in the 1970s but as of 2015 some pipelines built with this method remained in service.
Electric resistance welded (ERW) pipe is manufactured by cold-forming a sheet of steel into a cylindrical shape. Current is then passed between the two edges of the steel to heat the steel to …
Spot welding
Spot welding is a resistance welding method used to join two or more overlapping metal sheets, studs, projections, electrical wiring hangers, some heat exchanger fins, and some tubing. Usually power sources and welding equipment are sized to the specific thickness and material being welded together. The thickness is limited by the output of the welding power source a…
Seam welding
Resistance seam welding is a process that produces a weld at the faying surfaces of two similar metals. The seam may be a butt joint or an overlap joint and is usually an automated process. It differs from flash welding in that flash welding typically welds the entire joint at once and seam welding forms the weld progressively, starting at one end. Like spot welding, seam welding relies on two electrodes, usually made from copper, to apply pressure and current. The electrodes are …
Other methods
Other ERW methods include flash welding, resistance projection welding, and upset welding.
Flash welding is a type of resistance welding that does not use any filler metals. The pieces of metal to be welded are set apart at a predetermined distance based on material thickness, material composition, and desired properties of the finished weld. Current is applied to the metal, and the gap between the two pieces creates resistance and produces the arc required to melt the …
See also
• List of welding processes
Further reading
• O'Brien, R.L. (Ed.) (1991). Welding Handbook Vol. 2 (8th ed.). Miami: American Welding Society. ISBN 0-87171-354-3
External links
• Resistance Welding Manufacturing Alliance
• "Making Resistance Spot Welding Safer," from the Welding Journal
• "High-frequency electric resistance welding: An overview," from The Fabricator
• Video on YouTube by American Welding Society