EFW pipe manufacturing process

In EFW welding process, the external high energy electric arc is used to create a weld joint. Once the welding is done, the excess weld material from outside and inside of the pipe is removed with the help of trimmer tools.

In general, to reduce the negative effect of welding, a localized heat treatment of weld seam is carried out immediately it clears online ultrasonic test. Normally an induction heating method is used to restore microstructure of welded zone. These type of heat treatment is known as post annealing. In next stage, the pipe will go through Hydro testing, visual and dimensional inspection and once certified by inspection engineer it will send for packaging.

EFW steel pipes

EFW steel pipes

Manufacturing machine for EFW steel pipe:

A combination of specially designed equipments like 1600MT press brake machine, multiple rolls bending machine, welding installations for outside, inside and circumferential welding, size calibrating press, solution annealing furnace and a host of other related machinery, is employed to manufacture pipes used in critical applications like refineries, fertilizers, LNG terminals, cross country pipe lines etc.

Standard of EFW steel pipe:

ASTM A672 API 5L, ASTM A53 B, ASTM A178, ASTM A500/501, ASTM A691, ASTM A252, ASTM A672, EN 10217

ASTM A672 standard specification for electric fusion welded steel pipe for high pressure service at moderate temperatures.

This specification covers electrical-fusion-welded steel pipe for high-pressure service at moderate temperatures. Heat treatment may or may not be required to attain the desired properties or to comply with applicable code requirements. An analysis of each mill heat of plate material shall be made, also, an analysis of the finished deposited weld material from each 500 ft or fraction thereof shall be made. The mechanical test requirements includes one tension test specimen to represent each lot of finished pipe, and one transverse-guided-weld-bend test (two specimens) to represent each lot of finished pipe. Also, radiographic examination shall be made on the full length of each weld.

If you want to know more technical information about EFW steel pipes,please send email to us:sales@haihaogroup.com