| 摘要 |
A spray system has a pump with a double-action reciprocating plunger balanced to receive equal up-stroke and down-stroke assist from a pre-pressurized supply. The reciprocating plunger has identical working surface area on opposite first and second axial faces. A pumping system has a double-action reciprocating plunger with upward- and downward-facing spacers. The plunger travels axially within a proportioning cylinder with first inlet and outlet ports at a first axial end, and second inlet and outlet ports at an opposite second axial end. When the plunger is at its top-most position, the upward-facing plunger occludes the first inlet and outlet ports without blocking flow. When the plunger is at its bottom-most position, the downward-facing plunger occludes the second inlet and outlet ports without blocking flow. |
