Freyssinet – Freyssi flat jacks are a deformable steel capsule made out of two cold-formed steel halves welded together, presenting a circumferential circular toric rim.
Two pipe fittings, one of which serve as a vent, allowing a fluid to be injected under pressure to open the jack up to the height of the rim.
Freyssi Flat Jacks are simple, practical devices for the civil or structural engineer wherever the application or control of large forces is required. They are frequently used in the solution of unforeseen problems such as in remedial measures or structural additions.
They are as often used in new constructions in which they form part of the structural concept.