Vacuum Check Valve

FIG. 1 is a top perspective view of a vacuum check valve showing our new design;

FIG. 2 is a bottom perspective view thereof;

FIG. 3 is a front elevation view thereof;

FIG. 4 is a rear elevation view thereof;

FIG. 5 is a left side elevation view thereof;

FIG. 6 is a right side elevation view thereof;

FIG. 7 is a top plan view thereof; and,

FIG. 8 is a bottom plan view thereof.

The dash-dash broken lines in the drawings illustrate the portions of the vacuum check valve that form no part of the claimed design.