| 摘要 |
A system for dispensing coating material includes a source of coating material to be dispensed and a device for dispensing the coating material. The coating material is provided from the source under pressure to the device. The device includes a body having a passageway therethrough. A valve includes a valve seat provided in the passageway and a valve member for engaging the valve seat to close the valve and moving away from the valve seat to open the valve. In one embodiment, the valve seat and valve member are so dimensioned that when the valve member is against the valve seat, a portion of the valve member facing the valve seat is exposed to the pressurized coating material. In another, the valve seat, a downstream-most portion of the valve member, and a shoulder on the valve member are so dimensioned that the shoulder isolates the downstream-most portion from the liquid under pressure when the downstream-most portion is against the valve seat. In yet another, the valve seat and do wnstream-most portion are so dimensioned that when the downstream-most portion is against the valve seat, the downstream-most portion is not exposed to the pressurized coating material.
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