Porthole Vision Frame Office Doors - Glass Doors - Special Apertures

Porthole Vision Frame Office Doors;

Please Note: 

Apertures and doors were individually fire rated and tested; however as a unit they were not fire assessed and may not comply with fire standard requirements.

Office Doors with Special Apertures;

All our office doors with special round and square metal apertures (SlimPro and LoPro) are certified in the following manner, our door suppliers are able to provide proof of performance showing the individual door successfully completed a rigorous fire test to the BS 476 Part 22 standard or the European equivalent BS EN 1634, the fire rated aperture has then been separately tested and certified, the certification relates to a door and then the aperture individually and a dialogue should be undertaken with your planning and / or fire officer as to the requirements for compliance.

The ZEROplus top selling Slimport is a round metal porthole window (or circular vision frame to give its correct name) for installation in doors, walls and partitions.

Slimport metal porthole windows are available to suit four different door cut-outs: 250mm, 350mm, 450mm and 550mm. With countersunk holes in the bevel return on one side only, and 25mm screws that pass through the door cut-out and fix internally, the Slimport looks good aesthetically, and is totally free from visible fixings on the corridor side.


Slimport porthole window frames are available to suit the four most popular door thicknesses of 40mm, 44mm, 50mm and 54mm with a tolerance of ±2mm. The glazing pocket is 10mm wide (±2mm in relation to the door thickness) to accommodate 6mm-thick glass and appropriate glazing tape. If you have other door and glass thickness combinations please contact us for more information.

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