US Patent 6942255 Twist fitting for air tank connections

A fitting connector for a pressure vessel including a bushing for mounting within an aperture defined in a pressure vessel wall. The bushing includes a cylindrical bushing body having a head portion at one end thereof and including at least a pair of locking members for engaging along an interior surface of the pressure vessel wall. The locking members are provided with a contoured surface for engaging with detent members formed on the interior of the pressure vessel wall whereby the bushing is positively locked in a predetermined rotational orientation on the pressure vessel wall and is retained in place until a predetermined torque force is applied.