Hydraulic Globe Valves
The Hydraulic Globe Valves (HGV) control the flow rate of natural gas fuel to various stages of an industrial gas turbine combustion system. The unique design integrates the valve and actuator into a cost-effective, compact assembly. The valve is designed to provide a highly accurate flow-versus-stroke characteristic. The integral actuator is a single-acting spring-loaded design that will quickly close the valve upon loss of electrical or hydraulic signals. An integral hydraulic filter assure s the reliability of the servovalve and actuator components. The servovalve is an electrically redundant dual-coil design. A dc-powered LVDT (DCDT) provides feedback for the actuator.
The HGV design incorporates a pressure balanced metering plug which is directly connected to the output rod of a single-acting hydraulic actuator. A dual or triple coil electro-hydraulic servo valve controls the pressure applied to the actuator, and an integral hydraulic fluid filter provides protection against fluid contaminants. A DC-LVDT position feedback transducer is located within the unpressurized side of the actuator and is mechanically connected to the actuator piston. Fail-safe valve operation is assured by internal loading spri ngs. A visual stroke position indicator is provided on the actuator.
The valve stem seals achieve zero leakage of gas or hydraulic fluid from the assembly. Integrated hydraulic- or solenoid-initiated trip valves are available for fast shutdown by an independent system.
Optional features include various flow-versus-position characteristics, electric actuation, and the choice of ANSI B16.5 Class 300, 600 raised face flange or weld- neck-style connections.