Metu: METU insulated access door for round ducts with a 3rd plate (3PL) for a smoother inner-duct surface, better aerodynamics and additional insulating properties.

IRRD-3PL Insulated Access Doors

For circular ducts with outside or inside insulation
Simpler solution having lower insulating properties than the other insulated access doors
Suitable for all insulation thicknesses
Fitted with a third plate (3PL)

Illustration of the METU Access Door IRRD-3PL

Duct wall.
The cut edges of the insulation should be covered (with an aluminum tape for instance) in order to avoid chunks flying away. This should especially be done when the insulation is inside the duct in order to avoid contaminating the air in the ventilation system.
This access door consist of a standard RRD fitted with a 3rd plate (3PL) which has been spot-welded onto the inner cover plate, creating a hollow space filled with insulation.
The third plate (3PL) offers a smooth and aerodynamic surface. It can also be made of a thicker material upon request when a higher resistance to abrasion is required (i.e. pneumatic transport).
Unavoidable thermal bridge! The insulated access door IRRD-3DE offers better insulation properties.

The IRRD-3PL access doors are not available with NBR gasket and in stainless steel V4A. The high temperature (HT) versions are not available with the IRRD-3PL access doors made of aluminum.