PRV95, a pressure relief valve manufactured by Marotta Scientific Controls, provides an answer to premature wear and instability. Using an improved valve design, it provides stability over the entire operational range, from fully closed to fully open. The valve employs a concept known as upstream control for valve positioning, making it dependable with excellent repeatability and minimal lag time. PRV95 opens and closes softly, and does not oscillate or generate hard impacts. The PRV95 can maintain a seal near the set point of the relief limit. This new technology maintains seal integrity until 98% of set point and will reseat at 95–97% of set point. This allows the operator to protect a system without exceeding its limits. In the PRV95, the flow-limiting cross-section remains upstream of the valve seat at all times, and so the valve is said to operate under upstream control. The valve is primarily designed to operate in systems containing gases and liquids in a variety of pneumatic, hydraulic, and cryogenic applications. It offers several advantages, including a smooth transition from fully closed to fully open; noise and wear reduction through elimination of chatter; a decrease in the risk of product fire and explosion through elimination of hard impact; and corresponding reductions in the uncontrolled venting of hazardous fluids and products. The increased stability of the valve operation results in better performance, with wider operating ranges and control. These attributes translate into the additional advantage of lower life-cycle costs.
