| 摘要 |
<p>The seal is formed by two engaging surfaces of a sealing disc and the valve housing. The disc consists of PTFE and has numerous concentric micro-grooves, which correspond with grooves in the sealing surface of the valve housing, this surface being of a metallic material. Alternatively, the sealing disc may be cone-shaped so that the closing of the seal, the external sealing surface is the first to engage on the level sealing surface of the valve housing.</p> |
