| 摘要 |
<p>A plug valve comprises a plug rotatable in a body of plastics. The plug fits closely within a thin walled metal can. The valve body is formed by moulding around the can and plug, the can thereafter remaining fixed within the valve body, while the plug is rotatable in the can. Seals which are also embedded in the valve body during moulding project through the fluid passage openings in the can to engage the surface of the plug. The provision of the can prevents damage to the plug during moulding of the valve body and prevents the plug from being bonded to the valve body, or the valve body shrinking onto the plug.</p> |
