GESTRA Blowdown Valves
Continual evaporation in the steam generating unit increases the dissolved solids content of the boiler water. This must be kept within the limits set by the boiler manufacturer, however, which are governed by the applicable directives. The boiler water or blowdown must therefore be evacuated either continuously or at intervals.
This is the task of the BAE valves. Their wear-resistant nozzle stem has a special geometry, whereby the needle is centrally located when it enters the system of nestling expansion chambers. Here, continuous boiler blowdown takes place at a very high differential pressure. The BAE valves are designed for operation in steam generating plants that conform to TRD 604, EN 12952 and EN 12953.
Intermittent blowdown is achieved by the valve cone opening very quickly. This briefly produces "vacuum" at the bottom of the boiler. The resulting suction removes settled sediment on the floor of the boiler, also known as boiler sludge, from the boiler. The blowdown action is only effective for the first two seconds. Longer opening times lead to water losses.
The boiler pressure supports the closing force of the MPA valve spring, so that the valve closes reliably. The primary area of use is steam boiler plants. The intermittent blowdown action of the valves is triggered by controls such as the TA 7, for example. The control consists of an electronic cycling timer, a three-way solenoid valve and a strainer.