tête mécanique

CONT: [...] le second [type d'outils de piquage] consiste en une selle percée d'un trou taraudé ou à brides qu'on fixe à la conduite sous pression, et sur laquelle on monte un robinet. Le robinet en position ouverte, on y insère le foret et on le tourne manuellement ou au moyen d'une tête mécanique pour percer la canalisation [...]

CONT: ... the other type [of equipment for the installation of valves on water lines] makes use of a flanged or tapped opening in a saddle which is first attached to the water main and a valve is attached to the saddle by thread or flange, and with the valve open and the drilling equipment in place, the drill passes through the open valve and is turned manually or with a power head in order to drill the required hole in the water main.