| 摘要 |
<p>Valve body or stopper 1, for screwing into a liquid-filled system, is divided by a partition 2 into an inner chamber 6 accommodating a valve ball 8 loaded by a spring 7 into a valve opening 3 in the partition 2, and outer chamber 9 through the wall of which are a plurality of vent openings 10. Closure plug 13 screws into the chamber 9 and has a stem 12 on which are stopper rings 14 which swell upon taking up moisture and which register with the vent openings 10 so as to close the latter if liquid penetrates the valve opening 3. To enable the system to be bled manually as desired, a spindle 17 extends axially through the stem 12 to protrude by one end from the plug 13. At the other end the spindle 17 carries a pusher portion 19 by which the ball 8 can be unseated, this pusher portion 19 having, at its end facing away from the ball 8, a closure surface which serves, when the ball 8 is not being lifted, to seal the facing end of the channel, in the stem 12, through which the spindle 17 extends.</p> |
