Access Door RRD with NBR Gasket (up to 80°C)
Liquid-tight Version

Only three dimensions: RD 18, RD 21, RD 32

Only suitable for ducts with a clean and smooth surface without seams.

Internal tests demonstrate that the access doors remain oil-tight with an overpressure of 10'000 Pa. Since the conditions on the construction site are never ideal, and because the quality of the ducts does vary, no definitive guarantees can be given regarding the tightness, especially in the long term.

Max. operating temperature: ≈ + 80°C.

  1. Duct wall.
  2. Press formed covers (original METU-Design available in galv. and stainless steel V2A + V4A, alu.).
  3. NBR Gasket.
  4. Sealing rings made of NBR.
  5. Mushroom head bolts.
  6. Steel springs.
  7. Locking nuts prevent the knobs from being totally removed.
  8. Ergonomic and corrosion resistant knobs which do not allow the bolts to protrude (protected design).
  9. Retaining cable with M6 bolt and nut (D01V-2001) preventing the loss of the door.

Duct Wall Thicknesses
RD access doors with NBR gasket: S1 = max. 5 mm
For thicker duct wall thickness special access door versions with longer bolts can be ordered.

Top Required Clearance when Installed
RRD 18: H ≈ 36 mm
RRD 21: H ≈ 40 mm
RRD 32: H ≈ 55 mm

The steel knobs require the same clearance since the same bolt length is required to operate the access door properly.

List of Products & Prices

Opening Dimensions


RRD opening dimensions
according to the duct-Ø


Installation Instructions

Installation Video

Texts for Tenders


STP Dokuments

Made by METU in Germany