Control system for controlling gas fuel flow.

摘要

An apparatus (10) for accurately controlling gas fuel flow to a combustion device is provided to control gas flow to a burner (48) of the combustion device. A variable orifice solenoid operated valve (12) serves as a control element. The valve (12) includes a poppet (22) having a fixed control surface at an end received in an insert element (26) having a variable control surface. The poppet (22) has a plurality of positions within the insert element (26), including a full open position and a full closed position. Maximum fuel flow is measured in the full open position and minimum fuel flow is measured in the full closed position. Intermediate partially open positions are adjustable by a signal of an electronic controller (16) connected to the solenoid valve (12) operating as a function of actual and desired temperature of the combustion device.