摘要 |
A temperature control valve that effectively manages fluid pressure therethrough, including pressure differentials which may exist therein, such as from the upstream port to the downstream port, and about a piston slidingly disposed therewithin proximate a fluid flow path. In one embodiment a 3 stage valve is provided whereby fluid flows therethrough when the piston is in a first position, fluid flow is inhibited in a second piston position, and an override third position whereby fluid flows therethrough. When the piston is in the second position, the fluid pressure differential across the piston is balanced and an axial spring force on the piston is relatively small, thereby reducing any subsequent axial force required to advance the piston to the third free flow position, and allowing the valve to be comprised of cheaper materials including plastic.
|