Calibrated Plate

The calibrated plate is located inside the discharge nozzles in order to control the exact amount of gas to be discharged. As its name indicates, it is a circular plate with a central orifice calibrated according to the hydraulic calculations (calculation software). The diameter of the central calibrated orifice is stamped on the lower flat part of the nozzle. Its size is expressed in millimetres to two decimal places (e.g. 12.25 mm).

Calibrated plates must be fitted into every nozzle which is connected to cylinders or banks of cylinders with more than one nozzle to protect one or more hazard areas.

In modular cylinders with a single nozzle, it is not necessary to use a calibrated orifice. Nor are they necessary in pre-engineered and balanced systems with 2 or 4 nozzles, provided that the distances and requirements of those systems are complied with. They are supplied from the factory assembled in the nozzles.