These are installed on walls to isolate flow through square or round openings as well as in gravity channels. Stainless steel sliding PENSTOCKS are an ideal technical solution for most applications. These units can be supplied with rising or non-rising spindles for ON or OFF seating pressure. Manually, electrically or even hydraulically action is available with central directly mounted headstock or protruding headstock with a variety of mounting brackets configurations. Fixing of the units can be directly on walls with intermediate sealing material or instated into recesses with cement base sealing.