The “TÜV NORD” certificate confirms that the airtightness of the METU RD and GX access doors is much lower than the admissible leakage of the highest airtightness classs D (DIN EN 1507) and ATC2 (EN 16798-3), assuming the access doors have been properly installed according to our instructions.
One should especially make sure that:
Given these performances it can be assumed that the D / ATC2 classes are also easily reached by the RRD access doors (access doors for round ducts).
Oil-tight access doors: RD with NBR for rectangular ducts and RRD with NBR for the METU-FORM ducts (and also the inspection ducts) or longitudinally butt-welded round ducts.