Difference Between ERW Pipes, Seamless Pipes & Spiral Weld Pipes
One of the most common questions we face from our clients is what is the Difference between ERW, SPIRAL WELD & SEAMLESS PIPES?
ERW PIPES
ERW Pipes or Electric Resistance Welded Pipes are manufactured using mild strips of LOW CARBON STEEL COILS. The strips are passed through a series of Fin Rolls to make them into a rounded tube. The rounded tube in turn is passed through a series of forming rollers to produce a seam in the pipe which is longitudinal. The welded pipes are then passed through sizing sections where any dimensional deviations are corrected.
The Galvanized or GI Pipes sold by us are also ERW Pipes. GI Pipes are Steel Pipes dipped in Hot Zinc to galvanize them. The advantage of using a Galvanized Pipe is that the extra coating of Zinc helps in making the pipes Resistant from rust when the pipe comes in contact with water.
Inlay man’s terms, ERW PIPES are STEEL PIPES with a LONGITUDINAL JOINT.
ERW PIPES are manufactured from sizes ½” (15nb) to 20” (500nb) in INDIA.
ERW PIPES are used for applications like Fire Fighting, HVAC, Gensets, Plumbing lines, etc
The brands of ERW Pipes which we offer to our clients are JINDAL STAR PIPES, JINDAL HISAR PIPES, APL-APOLLO PIPES, PRAKASH SURYA PIPES. All the ERW pipes produced in India are as per IS Standards (IS:1239 & IS:3589)
SPIRAL WELD PIPES
Spiral Weld Pipes are also manufactured using HR STEEL COILS. The difference is that the coils are unwound and flattened. The flattened strips are formed into a cylinder of the desired diameter using angled rollers. The weld runs around the outside of the pipe in the shape of a Felix. This allows for a lot more flexibility when it comes to manufacturing larger diameter pipes in terms of both diameter and size.
In India, Spiral Weld Pipes are manufactured from sizes 22” (550NB) to 64” (1600NB).
The main manufactures of Spiral Weld Pipes are JCO GAS PIPE LTD. & STEEL AUTHORITY OF INDIA LTD.
We, at Vijay Sales Corporation, can offer larger dia pipes to our clients up to 64”. However, there is an extended lead time as all Spiral Weld Pipes are made against order.
SEAMLESS PIPES
As the name suggests, Seamless Pipes are those Steel Pipes that do not have a Seam and are NOT Welded. Since seamless pipes do not have any seams, they can withstand very high pressure and are ideal for applications like Boilers, Steam Lines, Oil & Gas. Typically, Seamless pipes can withstand a 20% higher working pressure as compared to Seamless Pipes. However, they are much more expensive as compared to ERW Pipes.
There are 2 main methods of Manufacturing Seamless Pipes:
MANDREL MILL PROCESS
Under this process, a solid steel round billet is used. The billet is heated to a very high temperature inside a rotary hearth furnace. With the help of a rotary piercer, a cylindrical hollow is made inside the billet and a set of roller arrangements is used to keep the piercer at the center of the billet.
The outside diameter of the piercer is approximately that of the inside diameter of the finished pipe. With the help, secondary roller arrangement outside diameter and thickness are achieved.
2. MANNESMANN PLUG MILL PIPE PROCESS
The only difference between the Plug mill process and the mandrel mill process is that in the mandrel method inside diameter is achieved in a single pass whereas in Mannesmann multi-stage reduction is possible.
Vijay Sales Corporation is the leading Distributor of Maharashtra Seamless Ltd. (MSL) & United Seamless Tubular Pvt Ltd. which are India’s leading manufacturers of Seamless Pipes. Seamless Pipes are manufactured from ½” (15nb) up to 20” (500nb).
Seamless Pipes are as per ASTM (American Society for Testing & Materials) Standards. Seamless Pipes are also IBR (Indian Boiler Regulations) Approved.
