Each Flowrox Knife Gate Valve is fully loaded and originally equipped with a flushing port, limit switch mounting, locking gate, and both top and bottom stem protectors. Each Larox knife gate valve has a heavier thicker gate and a “J” ring seat design that is able to withhold higher pressures than the conventional “C” ring design. Removable seats on both sides of the blade provide a bi-directional bubble tight seal in which absolutely no parts of the metal are exposed to slurry.
When a Larox Knife Gate Valve is in the open position the two sleeves seal against each other in the center, providing a full bore that allows the slurry to travel through without touching any metallic components. When closing the valve, the gate is forced progressively downward as it nears the fully closed position. At this point, the sleeves are sealed tightly against both sides of the gate so that the line pressure is completely and efficiently contained.
How the rubber sleeves work
In the valve housing there are two matching rubber sleeves that seal tightly against the gate when the valve is in the closed position and suction together when it is in the open position. This tight seal provides the high internal line pressure, which, in combination with the double seated sleeve design, also permits perfectly tight shut-off. There is a wide variety of sleeve materials available for different process needs.
Larox Knife Gate Valves have elastomer secondary seals that replace the merely conventional gland packing. These elastomer secondary seals perform both wiping and lubricating actions to the blade as it strokes down into the silicone filled grease contours of the seal itself. This type of lubrication of the blade allows for easer actuation and movement. The elastomer secondary seal’s lifespan is longer than competitors, but when a replacement is necessary, there is no need to remove the valve from the line.