The Industrial Division of North Carolina-headquartered Curtiss-Wright, recently announced that it has launched a new changeover valve (COV) from its brand family of Farris Engineering.
Designed in conjunction with their sister business, Phönix, and sold under the Farris name, the optimized COV is a three-way globe valve used in combination with Farris pressure relief valves wherever a shutdown cannot be tolerated. Changeover valves enable pressurized systems to be equipped with dual relief devices, allowing for maintenance to the relief devices without interrupting system overpressure protection. For critical services, a second change over unit can be added at the outlet of the relief valves allowing for collection of toxic or aggressive effluent into a closed collection system.
The changeover units were designed according to the appropriate industry requirements, including ASME B16.34 BPVC, ISO40126, API 520.2, EN19, and AD 2000 A2. The COV is offered with metal seating, Model 320B, or an optional bellow sealed stem, Model 370B, for toxic or lethal service. Optimized flow through the valve is guaranteed regardless of design. The optimized interior flow path results in a lowered deflection angle and reduced pressure loss within the COV. The result is less than a 3% pressure drop to the COV outlet or active PRV inlet.