Difference between Seamless and ERW Stainless steel pipe

Today, Prime Steel will discuss about the key difference between Seamless and ERW Stainless Steel Pipe

What is the Raw material required for manufacturing Seamless & ERW Stainless steel Pipes?

Seamless Steel Pipe is made from a solid round steel ‘billet’ which is heated and pushed or pulled over a form until the steel is shaped into a hollow tube. 

What is the Difference Between Seamless and ERW Stainless Steel Pipes?

Electric Resistance Welding (ERW) pipe is manufactured by rolling metal and then welding it longitudinally across its length. 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.

In Seamless pipe, there are no welding or joints and is manufactured from solid round billets. The seamless pipe is finished to dimensional and wall thickness specifications in sizes from 1/8 inch to 26 inch OD. Applicable in for High-pressure applications such as Hydrocarbon Industries & Refineries, Oil & Gas Exploration & Drilling, Oil & Gas Transportation and Air and Hydraulic cylinders, Bearings, Boilers, Automobiles etc.

ERW (Electric Resistance Welded) pipes are welded longitudinally, manufactured from Strip / Coil and can be manufactured upto 24” OD. ERW pipe cold formed from a ribbon of steel pulled through a series of rollers and formed into a tube which is fused through a electric charge. It is mainly used for low/ medium pressure applications such as transportation of water / oil.  

What Technologies are used to manufacture Seamless & ERW Pipes?

Technologies for Production of Seamless & ERW Pipes “CPE” Technology” used for Seamless Pipes & Tubes Production up to 7-inches OD is the world renowned Technology. “Plug Mill” Technology used for Higher Dia. Seamless Pipes & Tubes Production from 7-inches to 14-inches,is the most reliable technology,in higher dia. Segment. High frequency Induction Welding Technology is used for ERW Pipes &Tubes upto 21-inchesOD.

How to Identify Seamless or ERW Stainless Steel pipes?

To identify that a pipe supplied is seamless or ERW, Simply read the stencil on the side of the pipe

If it is ASTM A53, Type S means seamless.

Type F is furnace but welded,

Type E is Electrical resist welded.

Thats how. It is the easiest way to identify wether pipe is seamless or ERW.