Centerline Indications

By E.R.Cauffman Date 09-17-2002 14:20

Currently I am the welding engineer for a tube and pipe manufacturing facility that produces primarily 300 series stainless steel pipe. The problem I am encountering is a " centerline indication" that I know and feel is directly related to the speeds at which we are currently running.
Aside from slowing mill speeds down and/or installing an "arc deflection
unit" are there any other alternatives to be considered to remedy this problem?
Any and all comments or suggestions will be greatly appreciated.

Respectfully, E.R. Cauffman

By G.S.Crisi (****)

Date 09-17-2002 20:52

I'd like to make a few questions to clear up my mind.
1. Are the pipes welded or seamless?
2. If welded, are they resistance or submerged arc welded?
3. If seamless, are they rolled or extruded?
These questions are important to figure out a satisfactory response for you.
Giovanni S. Crisi
Sao Paulo - Brasil

By E.R.Cauffman Date 09-18-2002 09:39

Thank you for your timely response.
All welding in question is done with a duel process. Plasma welded first, and followed immediately by Tig weld both inside and out (Plasma Keyhole process with a tig wash).
These welds are being made on a continuous roll forming mill(flower design). Longitudinal welds can be produced in lengths of up to 60 feet on a continuous basis. Sizes range from 1/2 inch in diameter up to 96 inches in diameter. Wall thicknesses of the base material range from .062 to .500 however the problem seems to be primarily on the smaller diameters where speeds are significantly higher.

E.R.Cauffman
Bristol, Tn.

By JINX

Date 09-19-2002 20:13

Mr. Cauffman
What type of "centerline indications" are you encountering?