Lightweight aluminum construction is resistant to environmental and internal corrosion.

Repetitively consistent opening pressure.

Smooth relief action.

Positive reseating with minimal pressure drop.

Soft seat option provides repeatable leak-tight performance; allows reduced maintenance costs, multiple cycles with tight shut-off and high seating integrity (Models 330, 330S and 333S).

Model 230 (non-code) is direct spring-loaded design with synthetic disc insert.

Model 330 series’ differential mechanism maintains a predetermined seat contact load.

Full spring load is never imparted to synthetic disc insert (Models 330, 330S and 333S).

Seat tightness increases as inlet pressure approaches set (opening) pressure.

Each valve tested and inspected for pressure setting and leakage.