Accession Number : AD0464162
Title : STRENGTH OF SILVER-BRAZED PIPE JOINTS UNDER DYNAMIC LOAD
Descriptive Note : Final rept.
Corporate Author : DAVID TAYLOR MODEL BASIN WASHINGTON DC
Personal Author(s) : Zilliacus, Stephen
Report Date : Apr 1965
Pagination or Media Count : 41
Abstract : Destructive dynamic load tests conducted on specimens of copper- nickel pipe joined to bronze couplings by Grade II silver-braze alloy bonds. The bond areas varied from 9 to 85% of the total surfaces available for bonding. Every failure occurred in the bond. Cracking of the coupling sometimes accompanied bond failure. In no case was there rupture of the pipe. Since many joint failures apparently were influenced by a coupling geometry with abrupt changes in cross section, a modified coupling design is proposed. The dynamic forces required to produce failure of silver-brazed joints having less than 40% bond were considerably smaller than static failure loads in tests conducted elsewhere on similar specimens. For joints with with more than about 60% bond, the dynamic force valves were of the same magnitude as the static loads. Joints having more than 60% bond failed only after considerable elongation of the pipe. For sufficiently great initial dynamic force, joint failure occured immediately; otherwise two or more loadings were required. Impact velocities associated with joint failures ranged from about 1.6 to about 31 fps. It appears that the current practice of rejecting joints having less than 60% bond is justified for dynamic loading.
Descriptors : *JOINTS , *SILVER SOLDERS , STRESSES , LOADS(FORCES) , TENSILE PROPERTIES , TEST METHODS , STRAIN(MECHANICS) , PIPES , ULTRASONIC RADIATION , SHEAR STRESSES , BONDING , DUCTILITY , FAILURE(MECHANICS) , BRAZING
Subject Categories : Fabrication Metallurgy
Couplers, Fasteners, and Joints
Distribution Statement : APPROVED FOR PUBLIC RELEASE