Welding With/Without Filler Material

There are different process for welding without filler material and welding with filler material. ERW (Elect. resistance welding) pipes are generally manufactured not using filler material, while spiral welded pipes are manufactured using filler material. Both the procedures are approved and gives 100% efficiency joints of radiography quality.

Thanks Mukesh for your reply.

But i don't reckon you understand the essence of my question. i know what is welding with or without filler material but my question is more than that.

Yes you are right. I could not understand the exact essence. I am sorry for that.

ASME section IX gives some explanation as below;

The welding without filler material do have some disadvantages as the chemistry of the moten pool gets changed due to oxidation and other solution reactions of some of the alloying elements and thus the weldment chemistry will be different then the parent metal. By the addition of the proper filler metal in welding, this change in chemistry of the weld metal can be controlled to get the composition of the weld metal approximately same as that of parent metal.

Some procedures do eliminates addition of filler wire by the design of weld in that way and after qualification same is applied for the production purpose.