| 摘要 |
<p>A pressure regulating device for fluidtight, fluid-filled apparatus comprises a solid body with a shallow recess 4 in a surface enclosed by a flexible diaphragm 6. A narrow passage 5, preferably of capillary dimensions, connects the recess to the interior of the apparatus and the diaphragm is flexible enough to be deformed without injury so as to enter the recess and reduce its volume substantially and preferably practically to zero. The recess contains a volume of air which for optimum performance should be equal to the amount by which the volume can be reduced by movement of the diaphragm and also equal to the volume expansion of the fluid (or if more than one device is fitted its share of the fluid) from atmospheric conditions to mean working temperature (less the volume of any air occluded elsewhere in the apparatus). By this means, the diaphragm is substantially unstressed both under atmospheric conditions and under mean working conditions, since the gas will be compressed to a negligible volume.</p> |
