Gas-tight Shut-off Dampers Type ‘NAK’

FOR THE GAS-TIGHT SHUT-OFF OF DUCTS

Gas-tight shut-off dampers are designed to ensure the level of tightness required by KTA Guideline 3601 (German Nuclear Safety Standards Commission, KTA) and by DIN 25414 even when the power supply or compressed air supply fails.

  • Compact design and robust actuator mechanism allow for any installation orientation
  • Maximum air leakage rate is 0.0028 (l/s)/m² or 0.01 (m³/h)/m² at a differential pressure of 2000 Pa
  • Gas-tight closure, even when there is no power, due to special over centre locking mechanism
  • Variants with hand wheel, pneumatic actuator or electric actuator
  • Brass and stainless steel bearings
  • Powder-coated casing and blades
  • Maximum pressure loading of 5000 Pa, in closing direction
  • Available in standard sizes and many intermediate sizes

 

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Product Information

Optional equipment and accessories

  • Flange holes
  • Limit switch
  • Double acting pneumatic actuator, with optional solenoid valve
  • Electric actuator 3 × 230 V AC (400 V AC) or 230 V AC

  • NAK-H: Gas-tight shut-off damper with hand wheel
  • NAK-P: Gas-tight shut-off damper with pneumatic actuator
  • NAK-E: Gas-tight shut-off damper with electric actuator (400 V AC, 50 Hz)
  • NAK-E1: Gas-tight shut-off damper with electric actuator (230 V AC, 50 Hz)

  • Duct connection without flange holes
  • G: Flange holes on both sides

  • Attachments: For opening and closing, and for capturing the blade end positions

  • Casing made of welded U-channel sections, material thickness 3 mm
  • Blades and special sealing frame, material thickness 2 mm
  • External blade mechanism (over centre locking)
  • OPEN blades rest against the travel stops
  • CLOSED blades are pressed against the seal
  • Special sealing frame fitted with glued-in seals, welded into the casing

 

  • Casing made of sheet steel, material no. EN 10142-DX51D+Z150-200
  • Blades and sealing frame made of sheet steel, material no. EN 10327-DX51D+Z150-200-NAC
  • Linkage, travel stops and further attachments made of galvanised steel
  • Brass or stainless steel bearings
  • Seals made of neoprene rubber foam, temperature resistant up to 80 °C
  • Powder-coated casing and blades, grey (RAL 7001)

  • Closed blade air leakage to KTA 3601 Guideline (German Nuclear Safety Standards Commission, KTA) and DIN 25414
  • Casing air leakage to EN 1751, class C

  • Contamination should be removed as it may lead to corrosion
  • Lubricate friction points and bearings
  • NAK-H, NAK-E, NAK-E1: Lubricate threaded spindle
  • Lubricating intervals depend on the application: every six to twelve months or after a maximum of 2000 switching cycles
  • Use only oil or grease that is free of resins or acids.
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