Curtis Valves standard designs are spring loaded closed. Valve springs are made from non-corrosive, long lasting stainless steel. Valve bodies and moving parts are manufactured to precise standards with low tolerances and are available in stainless steel, anodized aluminum, brass, and cadmium or nickel-plated brass. Most seals are made of a specially compounded “cure dated” synthetic rubber to withstand a wide variety of liquids over a broad temperature range. Our valves use a wedge seal design which helps to prevent leakage and improve seal life.