2.2.1. Pressure Relief Damper for high opening pressures, with control function KL-E

In a great variety of different applications within HVAC systems pressure relief dampers manufactured by Krantz are used to limit the pressure and control it, respectively. Typical applications include the protection of ductwork from inadmissible high loading caused by positive pressure or negative pressure, positive pressure ventilation of staircases, or setting a defined pressure drop between adjacent rooms.



Dimensions W x H x D 800 x 500 x 620 mm
Weight 36 kg
Range of air flow 1 4 725 l/s [17 000 m³/h]
Opening pressure, adjustable 1 100 - 2 300 Pa

1 Higher range of volume flow achievable by parallel connection of several dampers


  • Airtight according to EN 1751, class 4 in closed position opens when opening pressure set is attained
  • Almost equal differential pressure independent of range of volume flow (control function)
  • Closes automatically when opening pressure is underrated
  • Setting of opening pressure by variation of lever arm


The Pressure Relief Damper KL-E is a design variant provided with control function which, as soon as then opening pressure is exceeded, keeps nearly constant the pressure in the ductwork, independent of the range of volume flow. When the pressure in the ductwork reduces to its normal range after the malfunction has been remedied, the damper closes automatically.