Seal Design Modification for AFRPL Stainless Steel Threaded Connectors
Abstract
An analysis of excessive connector helium leakage indicated that the radial sealing forces in the 1/2-, 3/4-, and 1-inch AFRPL stainless steel threaded connectors were too low to overcome manufacturing variations in the metal-plated seals. A program was undertaken to investigate three candidate materials for increasing the radial sealing forces in these three connector sizes, and to reassess the adequacy of the specification by which the seals were plated, i.e., MIL-P-27418 (USAF), Military Specification, Plating, Soft Nickel. Selected material properties, including yield strength and corrosion resistance, were investigated for cold-worked Type 304 stainless steel, Armco 21-6-9, and iron-base superalloy 19-9 DL. Preliminary tests were conducted for seal designs for each material, and verification tests were conducted for seal designs for Type 304 and Armco 21-6-9 stainless steel. Plating companies were contacted concerning the adequacy of MIL-P-27418 (USAF). It was concluded that the plating specification is satisfactory if the inspection is done with a 5-power glass. It was also concluded that modified seal designs utilizing cold-worked Type 304 stainless steel will achieve the desired performance requirements in the 1/2-, 3/4-, and 1-inch connectors and that the same seal designs utilizing annealed Armco 21-6-9 will probably achieve the desired performance requirements. It was recommended that the necessary changes be incorporated in the plating and connector specifications.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1970
- Accession Number
- AD0877207
Entities
People
- J. V. Baum
- N. D. Ghadiali
- T. M. Trainer
Organizations
- Battelle Memorial Institute