Knife gate valves
Conventionally, knife gate valves are used in the case of liquids with low solids content. Solutions with a peripheral seal are best suitable at dirt-accumulating locations and with thick, slurry media, in which case the cutting properties of a straight knife gate can be utilised. All knife gate valves are a good choice for confined spaces owing to their short L dimension.
Our product range comprises knife gate valves with a peripheral seal and an O-ring seal. The advantage of O-ring seals is their favourable acquisition price. These valves are tight in one direction only and they are relatively susceptible to solids concentration.
High-class transverse seal and disc peripheral seal structure
At locations where there are problems with conventional gate valves, the transverse seal structure is used. In these valves, transverse upper seals of on the closing flap substitute for the gland. The design of the seal and a scraper integrated into the seal keep the knife gate surface clean whilste isolating the gate. In addition, the two-component body has a peripheral seal that seals the gap between the disc and the body. Unlike in the case of O-ring models, the medium does not induce seal wear. The conventional particle-collecting pocket does not form on the bottom of the gate; instead, the disc is sealed tightly against the peripheral seal and metal valve body. This also renders the valve bubble tight, which cannot be achieved in any other way. The valve body supports the disc, preventing solid particles (debris, loose material, etc.) from bending the disc and causing valve leaks. The pressure rating is typically PN 10, but ratings up to PN 100 are available.
The valves are at their best in difficult conditions, such as:
solids-containing waters, pulp industry pastes, black liquor, recycled paper water lines, sugar-containing waters, syrup and juice lines, high viscosity lines, pellets, flours, groats-like media, coal dust, dust, sludge, cements, etc.
The valves are modifiable for various applications. Tell us about your valve problems and we’ll find a solution for you.
Learn more about the Swiss SISTAG Wey knife gate valves we represent from the YouTube link provided.
For other models, visit the manufacturer’s website. Brochures, instructions for use, 2D and 3D models, and many other materials can be downloaded from the website.