Stopper for cylindrical filling port in compressed gas cylinder control valve unit comprises bung containing locking mechanism, balls protruding from bung and lodging in recesses in port in locked position

摘要

The stopper for a cylindrical filling port (12) comprises a bung (20) containing a locking mechanism (30, 36, 40, 26). In the locked position balls (40) protrude from the bung and lodge in recesses (16) in the port. In the unlocked position they are contained inside the bung. A tool is used to move the stopper from one position to the other. Independent claims are included for: (a) the use of the stopper to close the filling port on a compressed gas control valve unit; and (b) a control valve unit in which the filling port is closed with the stopper.