A valve cone is the operating and defining component of a cone valve. Conical in shape, a valve cone can either be dynamic, able to be rotated or moved in a valve body to adjust and control the flow of a fluid or gas, or it can be fixed, mounted in a single position permanently to add a desired property to the flow of a fluid. Dynamic cone valves are commonly used in high-end plumbing systems or to accurately control the flow of various gases. Fixed valve cones are used almost exclusively for high-end drainage control systems.
In one type of dynamic cone valve, the pointed end of the valve cone extends into a round hole or seat through which the fluid arrives in the valve. Turning the handle or knob of the valve raises or lowers the valve cone into the opening. When lowering the cone into the valve, the ever-widening diameter of the cone increasingly restricts flow until it presses against the valve seat, cutting it off altogether. Similarly, raising the cone causes the opening to become ever larger, permitting greater flow through the valve. This type of cone valve can be adjusted very precisely, which makes it useful in controlling gases and other fluids, such as in refrigeration or oxygen systems.
There is another type of dynamic cone valve; however, in this type, the cone is fixed in the seat and has a hole through it, much like a ball valve. Adjusting the handle or knob rotates the cone in the seat, revealing the hole, which allows fluids to pass through the valve. If the handle is turned again, the hole in the cone will be rotated back into the body of the valve, hiding the hole and stopping fluid flow. Like ball valves, this type of cone valve’s handle can only be rotated 90 degrees and is often used in a higher-end plumbing system as a water cutoff valve.
The final type of cone valve is the fixed cone valve. A fixed cone valve is not adjustable, but is instead put into a fluid system, typically near the end or outlet, to affect the flow of the fluid. In this type of valve, the valve cone is fixed inside a cylinder of greater diameter, with the point of the cone aimed opposite the flow of the fluid. When fluid flows through the valve at a low flow rate or pressure, it moves easily around the cone of the valve and continues on its path largely unaffected.
If the flow or pressure of the fluid increases, it becomes restricted by the valve cone and is forced around the base of the cone, which increases the pressure in a way similar to a jet engine. As the fluid leaves the valve, it does so in a highly agitated state that causes the fluid to disperse into a spray, which dissipates much of the fluid’s flow energy. This type of cone valve is typically very large and is most often used in a large-scale drainage system. In this type of system, the dispersion of the water flow caused by the fixed cone valve reduces or eliminates the soil erosion that would occur if the water was allowed to exit the drainage system in a single, high-pressure stream.