The Schubert & Salzer Control Systems’ sliding gate valve incorporates two slotted discs sliding against each other, and forming a seal. One sealing disc is permanently fixed in the valve body and the other is movable.
The conventional materials for the movable sealing disc based on carbon or stainless steel with a hard alloy based on cobalt and chromium (Stellite) are now supplemented by a diamond-like coating known as slide friction coating (SFC). Movable sealing discs coated with SFC can withstand high differential pressures while, at the same time, the actuation forces for moving the sealing discs remain extremely low. This makes it possible to have smaller and cost-effective valve actuators. Insensitivity to pressure shocks, operation near the closing point with improved edge stability and the relatively low leakage rate round off the advantages of this sliding disc coating.
The SFC coating not only improves the frictional properties of the base body but also forms an enveloping hard layer around the base material and protects it from chemical and mechanical attacks by the medium or by contaminants. Sliding gate valves with an SFC-coated sealing disc are for shutting off and controlling high differential pressures at low actuation forces and present an easy solution for dealing with carrier fluids, saturated steam, acids and caustic solutions.
