A knife gate valve serves as a ‘ninja’ that wields a blade to cut off blockages of heavy liquids in the pipelines. With the sharp blade, knife gate valves usually present in a situation where there is most corrosive, aggressive and abrasive

The pulp and paper industry is the one the knife gate valves were originally designed for. In the past, the viscous pulp will be caught between the wedge and seat of an ordinary gate valve, thus the flow stream can not be shut off. The knife gate valve there, with a sharp cutting edge, is able solve the problem and cut off the pulp and seal it.

How does a Knife Gate Valve Work

Out of this ingenious feature, knife gate valves have emerged to be more than popular when it comes to places that transport viscous fluids, slurry and other things alike.

Today, knife gate valves are used in many processing plants and are larger in size, which makes it easier to handle dense fluids such as light oil, heavy oil, varnish, mud, waste water, and pulp. It should be noted that these valves have low pressure limits, and after the blade cuts the material it handles, the blade will return to the elastomer seal. Thick liquid can smoothly slide over these soft seals, however, when solid substances or powders pass through the knife gate, these rough substances will eventually accumulate in the soft seal at the end of the knife gate. When this happens, the sealing performance of these valves will wane. If this happens, the seal needs to be replaced.

When not to Use Knife Gate Valves

Knife gate valves can not be used to regulate the flow stream, because vibration occurs when the fluid is forced to flow through a partially closed gate valve and erodes the wedge and seat. Therefore, the knife gate valve can be used only when it is completely closed or opened.