Valve.
Description:
Patent for improvement in valves, by means of assuring a tight operating stem. The stem is comprised of two movable sections incorporated into a design purposed to prevent leakage by the stem. Additional mentions include acknowledged awareness of susceptibility to change and modification, convenience and facility, and simplicity as related to cost.
Date:
December 24, 1918
Creator:
Pratt, Robert L.
Item Type:
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