There are four standard aperture sizes and each transit frame is made up of one or more apertures. The four standard sizes are as follow:
Size 2 60mm x 120mm installation area.
Size 4 – 120mm x 120mm installation area.
Size 6 – 180mm x 120mm installation area.n
Size 8 – 240mm x 120mm installation area.
Each aperture has a further area of 40mm x 120mm which is use purely to accommodate the installation of the compression system.
For items in excess of 100mm O/D the HCLX civil frames are available and will seal items up to 330mm O/D – see Transit manual.
Note: HCLX frames are designed for a single penetrating item only and no stayplates are needed or available for this type of frame.