DEVELOPMENT OF AFRPL THREADED FITTINGS FOR ROCKET FLUID SYSTEMS.

Abstract : Families of threaded connectors consisting of unions, elbows, tees, and crosses were designed for Type 347 CRES and 6061-T6 aluminum. Design procedures were programmed for a CDC 3400 digital computer. Development specimens were fabricated in both materials for 3/8- and 3/4-inch diameter tubing systems. Detail designs and preliminary MS standards and specifications were prepared for fittings made from both materials. Qualification tests included (1) proof pressure, (2) thermal shock from -320 to 600 F for stainless steel systems and -320 to 200 F for aluminum systems, (3) stress-reversal bending, (4) vibration, and (5) repeated assembly. Operating pressures were 4000 psi for stainless steel systems, 1000 psi for 3/8-inch aluminum systems, and 750 psi for 3/4-inch aluminum systems. Leakage was measured with a helium leak detector with leakage rates under all service conditions, consistently ranging below 7 x 10 to the minus 7th power atm cc/sec. Rene 41 connectors were designed and fabricated, and qualification tests were conducted on 1/2-inch unions and forged elbows and tees. Unions for joining aluminum and stainless steel tubing systems were designed and tested on a limited basis. In addition, an analysis procedure for estimating performance levels for threaded connectors was also formulated. (Author)