Root Face Clarification

thangaraj762005, root face for a butt weld joint serves three purposes: First it is required for producing a weld joint with full penetration. If the root gap is not maintained, full penetration weld joints are not possible. Thus your weld joint will be rejected in radiographic testing (if required at all). Second that the root gap helps in fusing the parent metal with the weld metal and thus making the welded joints with almost the same strength as that of the parent metal. Without root gap the weld strength of the welded joint cannot be maintained equal to that of the parent metal. Third that the root gap and the full penetration will ensure that there is no material discontinuity due to lack of fusion/ penetration. Thus the probable discontinuities/notches in the welded material are avoided. These notches act as failure points in welded joints. Thus the life of the welded product is increased by giving root gaps. A word of caution though: If the weld design specifies that the root gap is to be maintained, please maintain it. This will ensure the integrity of the equipment/piping system and avert a major accident/loss. Hope I have answered your query.