The valves find application in paper and pulp,
Gate Valves certainly are a specific sort of parallel gate valve which is designed to handle systems with higher content of suspended solids. The knife gate valves are specifically beneficial for handling slurry, viscous, corrosive and abrasive media. The valve owes being able to handle these fluids for the knife-edged disc, and that is capable of cutting through fibrous material, along with the virtual lack of a Gate Valve body cavity. The disc travels in lateral guides and is also forced up against the seat by lugs in the bottoom. If a high amount of fluid tightness becomes necessary, the valve can also be provided with an O-ring seat seal.
The valves find application in paper and pulp, minerals and metals, steel plants, thermal power plants and chemical/ petrochemical industries. Knife gate valve features a short face-to-face length as compared to other gate valves. As a consequence a knife gate valve is light weighted as compared to other gate valves.
These valves operate primarily in open/closed mode, although occasionally they can be useful for fluid regulation. In the open position, these valves are classified as “full flow” and make almost no pressure drops because the closing diaphragm completely clears the fluid flow. The sealing tightness of such valves is extremely good because there is no direct contact relating to the fluid along with the stem, however they require regular maintenance in order that the diaphragm was in good condition, particularly fluid is rich in solid particles. It is important to make sure that the membrane material is well adapted towards the operating temperature and pressure conditions in order to avoid premature wear.
Diaphragm valves are typically used in the meals and pharmaceutical industries. They are also frequently utilized in the chemical industry along with ultra-pure applications, based on the materials these are made of, especially the membrane. They are also ideal for sludge and highly viscous liquids.
Thermal binding takes place when a valve is tightly disconnect while the high temperatures system is operation. Later when the technique is shut down and able to cool, thermal contraction with the valve seats move inward greater than the wedge shrinkage. This can bind the wedge and seats tight enough to never allow the wedge to unseat or move if your hand-wheel or valve actuator is activated to spread out the valve.
Parallel seated gate valves are most well suited for applications having prospect of thermal binding. Split-wedge or flexible-wedge type gate valves are anticipated to perform much better than solid-wedge gate valves when thermal binding is often a concern.