ERW pipe vs EFW pipe

Electric Resistance Welding (ERW steel pipe): welding member combination is applying pressure through the electrodes, the use of current through the joint area of the contact surface and the adjacent heat generating resistance welding process method, Also known as contact welding. It has excellent toughness and dynamic load strength, welding deformation.
Commonly used spot welding, seam welding and butt three.

Electric Fusion Welding (EFW steel pipe) refers to an electron beam welding, the use of high-speed movement of the electron beam directed impact kinetic energy is converted to heat the workpiece so that the workpiece leaving the melt, the formation of the weld.

It is mainly used for welding dissimilar steel welding sheet or which high power density, metal weldment can rapidly heated to high temperatures, which can melt any refractory metals and alloys. Deep penetration welding fast, heat-affected zone is extremely small, so small performance impact on the joints, the joint almost no distortion. But it has a requirement on a special welding room because welding using X-rays.