摘要 |
<p>A tube valve 11 having a tube 34 that closes the valve by being moved to a position juxtaposed to a pervious support structure 27, 28 having a traversing impervious barrier 19 and that opens the valve 11 by being moved away from the support structure 27, 28 wherein the "water hammer" effect is minimized by tube movement resistance generated by the barrier configuration.</p> |