摘要 |
<p>A drain valve includes an inlet plenum, a first orifice downstream from the inlet plenum, a second orifice downstream from the first orifice, and a fluid passage between the first and second orifices. A piston having a first position and a second position has a first surface area exposed to the fluid passage when the piston is in the first and second positions and a second surface area exposed to the inlet plenum when the piston is in the second position.</p> |