摘要 |
<p>A pressure relief valve for releasing fluid through a vent in a railway tank car, tank trucks and similar vessels. A valve disk is normally biased in a closed position by a plurality of constant-force springs of laminated steel tapes on drums supported on upright angle brackets symmetrically arranged around a valve seat. The pressure at which the valve opens is determined by a preselection of the number of springs, laminated tapes per spring, and the restoring force of each tape.</p> |