摘要 |
<p>A sliding valve for withdrawing liquid or gaseous chemical products from a container has a cylindrical valve spool which slides axially in a bore through a valve housing. A first annular groove of the valve spool connects, in the open position of the valve, a product supply line to a product withdrawal line. On one side of this first annular groove there is a second annular groove which, in the open position, connects a gas supply line to a gas withdrawal line. An annular groove on the other side is connected to the second annular groove. By this arrangement, protective gas is admitted to the valve spaces on either side of the first annular groove, which handles the product, with the result that escape of the product to the outside, or penetration of impurities, are positively prevented.</p> |