Patent ID: 8733619
Filing Date: 2014-05-27
Classification: B23K,C10G,F16L,F28D,F28F

Abstract:
1. A method for making a nickel-base radiant tube including a straight tube section and a curved elbow tube section, said method comprising the steps of: a) providing said straight tube section having a first center line, an inner radius and an outer radius both substantially constant along an entire length of said straight tube section; b) providing said curved elbow tube section having a second center line, an inner radius substantially constant along an entire length of said elbow tube section and an outer radius varying along a portion of the length of said elbow tube section; said inner radius of said elbow tube section being substantially equal said inner radius of said straight tube section; said elbow tube section including a mating end portion having an outer radius substantially equal to said outer radius of said straight tube section, a main portion having an outer radius substantially different than said outer radius of said straight tube section, and a sloped transitional portion disposed between said mating end portion and said main portion of said elbow tube section; said outer radius of said mating end portion being substantially constant along an entire length of said mating end portion; c) forming an end face on each of a mating end portion of said straight tube section and said mating end portion of said elbow tube section; d) positioning said mating end portion of said straight tube section adjacent to and axially aligned with said mating end portion of said elbow tube section so that said end faces of said straight tube section and said elbow tube section facing each other to define a circumferentially extending weld groove; and e) butt welding said mating end portions of said straight tube section and said elbow tube section together at said weld groove.