The Fisher YD and YS three-way cage-guided valves are designed for throttling or flow-switching service. The design YD contains a balanced valve plug and typically used for general converging (flow-mixing) and diverging (flow-splitting) service. The design YS has an unbalanced valve plug and generally used for converging service, but can be used for diverging service with on-off applications only.
Flow Control Equipment maintains a large inventory of remanufactured YS and YD control valves in a variety of sizes and materials.