Honeywell V5051A Single-Seated Valve V5051A THE V5051A IS A CAGE TYPE, SINGLE-SEATED VALVE FOR CONTROL OF STEAM, AIR OR OTHER NONCOMBUSTIBLE GASES IN HEATING, AIR CONDITIONING AND OTHER SYSTEMS REQUIRING TIGHT SHUTOFF. IT IS USED IN TWO-POSITION, PROPORTIONAL OR FLOATING CONTROL SYSTEMS. A Q601K LINKAGE AND A MODULATOR MOTOR ARE REQUIRED FOR OPERATION. 0 V5051A » Provides tight shutoff with extremely low leakage. » Pressure-balanced cage type construction. + Sizes range from 2-1/2 to 6 in. (63.5 to 152.