NKTMJ – Non-Return/Back draft Damper closes at reverse airflows in HVAC systems and shut off duct automatically.

Characteristics

• Min. dimensions 200 × 200 × 210;
  max. dimensions 2 000 × 2 000 × 210 mm (square cross-section only, round adapter available)
• Only mechanical variant
• Plain bearings, maintenance-free design
• Max. permissible leakage via closed blades - 2% of nominal airflow
• External casing leakage class C acc. to EN 1751
• Max. airflow 25 m/s
• Variant with, or without counterweight - adjustable system

• Mechanism installed externally of the damper axis and airflow direction
• Pressure difference up to 7 500 Pa (internal vs. external pressure)
• Carbon steel painted, galvanized, or stainless steel – casings made of 3 mm sheets, welded construction
• Radioactive aerosol impact allowed - decontaminable
• Seismic resistant (high resistance)
• Guaranteed service life 40 years, recommended maintenance interval 10 000 hours