The CAT model FCA stop-log is provided with a square or rectangular port, sealed on 3 or 4 sides, depending on the version, and manufactured according to the dimensions required by the customer. It is normally installed in open channels. It is used for water treatment, power stations, hydraulic installations, purifying systems, etc...

The stoplog design consists of a frame and a sliding gate. In the model with 3 sealed sides the gate is divided in several sections while in the model with 4 sealed sides the gate consists of a single section.

Notwithstanding the material of the gate, the tightness is achieved by the contact between a soft seal joint and a stainless steel surface. The typical arrangement for this type of valve consists on having some frames imbedded in concrete and a set of gate sections to be mounted on any of them.