摘要 |
<p>The invention concerns a butterfly valve of a type wherein the elastomer sleeve lines the body bore, and has cheeks which fit into circular recesses provided in the two parallel radial faces of the valve, the shape of the cheeks and of the circular recesses being such that when the valve is assembled between flanges, the elastomer of the cheeks is pressed into a spare volume in the circular recesses and precludes any creep of the elastomer towards the core of the sleeve.</p> |