Often it is not possible to lay pipes in open ditches. For example, for rail or road crossings it is first necessary to drive casings underground. By using PSI steel insulators or roller rings, the carrier pipe can be inserted into the casing sleeve safely and efficiently.

Steel insulators are preferred over plastic insulators in the following cases:

high medium temperatures
strong pressure in large diameters (load-bearing capacity)
wide gap between casing and carrier pipe diameter (up to 600 mm)