Drain and vent system for boilers - has level controlled valve in collector and piston operated main valve

摘要

The arrangement for ventilating or draining is used in pipelines and boilers. The boiler has a pressurised collector vessel and main valve whose closing part is fully opened on draining and actuated by the float. The vent and drain systems can be used for a wide range of flow rates and flow cross sections. The main valve is a differential pressure valve charged on both sides with system pressures. The float is coupled to a control valve. The control valve is opened by the float at a certain liq. level in the collector tank. The pressure released in this position acts on the corresponding end of the piston in the main valve for opening this main valve. The double acting piston is held in the valve housing.