This technical condition applies to HB 5536-83~HB 5551-83 spherical pipe connectors. This type of connection is suitable for piping systems of aero-engines, and can also be used for piping systems of aircraft, missiles and their accessories.
HB 5535-1983 history
1970HB 5535-1983 Technical conditions for spherical type pipe joints
1970HB 5535-1981 Specifications for spherical pipe connectors