| 摘要 |
<p>A relief valve includes an outer stem including a larger diameter fitting section and a smaller diameter fitting section, a movable valve element fitted in both fitting sections so as to be moved between an opening position and a closing position, a communication space extending through the stem and the valve element so that a compressed fluid flows through the space, a first normally closed seal disposed between the valve element and the smaller fitting section for closing a part of a circumferential gap defined between the valve element and the stem, a second seal disposed between the valve element and the larger diameter fitting section for closing a part of the circumferential gap extending from the larger diameter fitting section side to the communication space when the movable valve element has been moved to the closing position, the second seal opening the part when the movable valve element has been moved to the opening position, a relief hole formed in the stem so that the circumferential gap normally communicates with an atmosphere outside the stem irrespective of a position of the valve element, a holder for holding the valve element at the closing position by means of a holding force, and a pressure wall protruding from the valve element inside the larger fitting section to move the valve element to the opening position side when a pressure in the communication space is increased to or above a predetermined value while the valve element is at the closing position.</p> |
