Opening Pressure Adjustment

To adjust opening pressure, change shim thickness. Thicker shims will increase opening pressure; thinner shims will decrease it. Shims are available in thicknesses from .040-.077" (1.00-1.95 mm) in increments of .002" (.05 mm). A .002" (.05 mm) shim will increase opening pressure by approximately 7 psi. (.5 kg.). See Figure .