Brazing rules

[Peter_1]

Belgium (F Gas exams) took over the Dutch STEK- rule that the filler material in a brazing must penetrate 100% through the gap.
Belgium didn't think nor analyzed if this in act really needed.
I saw on the website of Tradewinds whom offers a brazing training according to the British Refr. Ass. Standards and they say We then move into the theory on the brazing process and how to make sure you work to BRA Standards and achieve 100% penetration on all joints

Why is this needed?

I'm asking this because on the copper.org website, I read Although 100% penetration and fill of the capillary space fitting is desired, a solder joint fill of 70% fill (or no greater than 30% voids) is considered satisfactory to obtain joints that can withstand the maximum recommended pressures for soldered copper tube and fitting systems.

A major difference between brazed and soldered joints is in the amount of joint overlap or fill necessary to develop full strength of the joint. In a brazed joint, full insertion of the tube to the back of the fitting cup is still highly recommended; however, complete fill of this joint space throughout this entire length is not necessary to achieve full joint strength. According to the American Welding Society (AWS), it is suggested that the brazing filler metal penetrate the capillary space at least three times the thickness of the thinnest component being joined, which is usually the tube. This is known in the industry as the AWS 3-T Rule.


I suppose the Americans have thoroughly tested this before they published it.

Link http://www.copper.org/applications/p...explained.html

Why I'm asking this; if a candidate in the Belgium F-gas makes 3 solderings with < 50% gap filling, although completely gas-tight, full strength on pressure test, he/she fails.



Any comments?