| 摘要 |
<p>A liquid tank cap (10) incorporates a two-way relief valve in which an annular valve disc (16) has one side (56) sealed against a seal (18) adjacent to its inner diameter and the other side (60) sealed against a seal (14) adjacent to its outside diameter. When subjected to a pressure differential in either direction, the disc (16) deflects so as to increase its concavity and allow air passage by one or the other seal (14, 18), depending upon whether the pressure in the tank is subatmospheric or superatmospheric.</p> |
