Showing papers on "Bend radius published in 1968"

Tube bender with incremental tube measurement

Abstract: A NUMERICALLY CONTROLLED TUBE BENDER IN WHICH EACH BEND IS INCREMENTALLY PROGRAMED IN TERMS OF THE DISTANCE BETWEEN STARTING POINTS OF SUCCESSIVE BENDS, THE PLANE AND THE ANGLE OF THE BENDS. THE LENGTH OF TUBE USED IN MAKING EACH BEND, WHICH VARIES WITH TUBE CHARACTERISTICS, IS SUBTRACTED FROM THE PROGRAMED DIMENSION BETWEEN THE BEND STARTING POINTS AND THE DISTANCE BETWEEN THE END OF THE FIRST BEND AND THE START OF THE SECOND BEND IS ADJUSTED ACCORDINGLY.

The Influence of Bends on Fluid Transients Propagated in Incompressible Pipe Flow

Abstract: The influence of a bend on the fluid transients propagated by a rapid valve closure in a long pipeline is examined by means of a short dimensional analysis and a comprehensive series of experimental tests designed to record the effects of varying in turn: the pipeline diameter to thickness ratio (7.35 to 48), pipe elasticity to fluid bulk modulus ratio (0.27 to 93.6), the restraint applied to the pipeline, the bend radius of curvature to pipe bore ratio (0 to 5), the included angle of the bend (0° to 135°) and the initial flow velocity.From these tests the influence of a bend is found to be solely dependent on its geometry. Empirical formulae are proposed which express the reflection and transmission of a transient at a bend in terms of the bend radius of curvature to pipe bore ratio and included angle. The formulae are tested by varying both the angle and curvature of a series of bends mounted in turn in a steel pipeline and found to be accurate within the limits of measurement possible.A method designed...

Production techniques for the extrusion of thin lockalloy shapes.

Abstract: : A practical and economical production technique for long structural shapes of Lockalloy (38w/o Al and 62w/o Be) was provided. The technique uses a 'net' precision extrusion through complex shaped dies. The excellent surface quality and dimensional tolerances which were obtained eliminated the need for machining all surfaces of the sections, which was a requirement for most aerospace applications of Lockalloy before this work. Two typical structural shapes were produced, one a 1 in x 2 in x 1/16 in thick T-section and the other an unsymmetrical angle section having one leg 1 in long and 0.180 in thick and another leg 1 in long and 0.125 in thick. Techniques for straightening and detwisting extruded sections were optimized. Applicability of the extruded shapes to aerospace structures was demonstrated by forming T sections to a 10 in bend radius and by offset joggling sections by 3/16 in. Mechanical properties in the longitudinal and transverse directions of Lockalloy shapes were obtained at temperatures of -40F, room temperature, 200F, 400F, 600F, and 800F. These properties were found to be comparable to published data for rolled Lockalloy sheet. (Author)