| 摘要 |
<p>A valve body has outlet ducts to be positioned below the surface of the molten lead, and a head rotatable with respect to the body. The head has recesses which terminate in slots that can be aligned with the outlet ducts to open the valve. These slots have smaller cross-sections than the ducts. The body also has open ended passages which align with the outlet ducts when the valve is closed.</p> |
