摘要 |
<p>An expansible tube type valve wherein a flexible tube, which is sealed around its ends in a valve body, is stretched to seal around a barrier in the flow passage. Thin rings of thermal insulation material are disposed around the ends of the flexible tube, interposed between it and parts of the valve body normally in contact therewith, so as to isolate the tube from the body and preclude transmission of high temperatures thereto, as in the event of a fire in the area.</p> |