| 摘要 |
<p>A valve for adding ingredients to or sampling the fluid flowing through the valve includes an adjustable solid stem which can be extended through the flow path of a pipeline to form a seal with a seat positioned directly opposite the stem. An injection nozzle is fitted into the seat to permit addition of ingredients or sampling of the fluid when the stem is retracted from the seat. When the stem is seated, flow still occurs in the flow path.</p> |
