2007-04-30 05:43:10 · 3 answers · asked by wanadox 2 in Science & Mathematics ➔ Engineering
Joint efficiencies are numbers that are used to define the strength of a welded joint, based upon the amount of non-destructive testing that is done upon the completed joint.
There are other factors that enter into it also, such as the configuration of the welded joint, but basically it depends upon the amount of testing that is done.
If the welded joints are not radiographed at all, the joint efficiency could be as low as 60%.
If the joint is spot radiographed, the joint efficiency is 85%.
If the joint is fully radiographed, the joint efficiency is 100%.
These joint efficiencies are used by the equipment designers to determine the required thickness of the materials used in the design of their equipment. The allowable stresses of the materials used in their designs must be multiplied by the joint efficiency, so a boiler built with no x-rayed joints, would have walls that were almost twice the thickness of a boiler whose welds were fully x-rayed.
2007-04-30 12:39:00 · answer #1 · answered by gatorbait 7 · 3⤊ 1⤋
Joint Efficiency simple is the ratio of the Strength of the weld to the strength of the base or parent metal.
If the Joint Efficiency is 1, this means the weld is as good as the parent.
If the Joint efficiency is less than 1, this means the weld is weaker than the Parent.
Joint Efficiency is determined by 2 factors, the Type of weld and the Degree of Radiography.
For a Type 1 weld
For Fully Radio-graphed the Joint efficiency is 1
For Spot Radio-graphed the joint efficiency is 0.85
For no Radiography the Joint efficiency is 0.7
2015-01-31 14:37:24 · answer #2 · answered by Tejaswi 1 · 2⤊ 0⤋
Joint efficiencies as used in Section VIII (Rules for Construction of Pressure Vessel), Division I, Subsection B, Part UW-12 apply to joints completed by an arc or gas welding process. Except as required by Part UW-11 (Radiographic and Ultrasonic Examination), a joint efficiency depends only on the type of joint and on the degree of examination of any other joint.
2007-04-30 05:52:55 · answer #3 · answered by weisse_rakete 2 · 1⤊ 0⤋
A numerical value expressed as the ratio of the strength of a welded, or brazed joint to the strength of the parent metal. Consideration is appropriately given to heat effected zone and metallurgical effects of welding.
2007-04-30 05:55:24 · answer #4 · answered by Richard W 3 · 1⤊ 0⤋
Practice, after many years you can hear it, feel it and see it,
2016-04-01 02:14:49 · answer #5 · answered by Anonymous · 0⤊ 0⤋