Gauge, Purge, & Transducer Valves Description Hansen’s specially designed Gauge, Purge, and Transducer Valves feature tough, forged steel bodies, compact size, and polished stainless steel stems HGV1: Long Neck H9490: Transducer Valve H7771 H7772 H958C H7778. More Products Flange Unions Industrial Shut Off Valve for Ammonia Hand Expansion Valves Solenoide valves Cylinder liner and capacity control Piston, connecting rod and safety head