Crane Plumbing Pressure Valve

A lovely Crane valve that we are pretty sure is for some kind of pressure regulation. We're not positive... but it's cool! Feel free to ask any questions. Stamp reads "3/4 CRANE A. S. M. E. STD" on front. Bottom near screw area reads "85" and there is a stamp that says "84" on the top. Lever reads "89" (or possibly "68"). Back stamps say "CAP 250" "SET 15 LBS" and "NON ADJUSTABLE"

Condition: Considerable surface wear all over, but metal seems to be in good condition.

Dimensions:

Overall length: 4 inches

Overall width: 2 1/4 inches

Diameter of screw opening part: 3/4 inches

SKU: P-006-19
LOC: PC2