Double walled casings are available in standard diameters from 540/478mm up to 2000/1910mm. Lengths of 1, 2, 3, 4, 5 or 6 meters for the full range of casing diameters.
Casing joints are watertight and can be connected to either single or double walled casings.
The casings feature an outer wall thickness of 10-18mm and an inner wall thickness of 8-12mm that depend on the casing size.
For the ultimate in strength and rigidity, the casings incorporate a number of longitudinal reinforcing bars between the inner and outer wall. Smaller casings have 16-18 reinforcing bars, while the larger casings have up to 62. For the bulk of casing sizes, the combined (overall) thickness of the inner wall, gap/reinforcing bar, and outer wall is 40mm.