Gas burner control system

摘要

A burner control system for gas fired apparatus of the powered blower vent type wherein a diaphagm valve for controlling the supply of gas to the main burner of the apparatus is operated by a gas bleed line which is subject to pressure regulation by a servo regulator valve. The bleed line is also subject to on-off control by pneumatically operated bleed valve means which are responsive to the subatmospheric fluid pressure produced in the exhaust vent of the apparatus by an exhaust blower to permit opening of the diaphragm valve only when the fluid pressure level within the exhaust vent is sufficiently below atmospheric pressure. The control system preferably includes switching circuit means which are effective to energize the exhaust blower only during the existence of a pilot burner flame adequate to ignite the main burner.