In addition to the general outside the control of industrial processes, in the laboratory and pilot plant where there are still many need to control the flow of very small applications, such a small flow of its full-flow valve leakage than the average are still very small, so alone in general mechanical processing, the general process is not guaranteed, the only solution to the problem is the valve flow characteristics of each experiment calibration to the final calibration, concrete, real flow to illustrate.
Structure
Small flow control problems are usually resolved in two ways:
(1) in the standard use of special valves inside the valve body parts. This approach can usually be Kv = 0.03 or so.
(2) in the standard use of special valves inside the valve body parts has a good economy and scalability, as it will reduce the valve body and executive body of special spare parts requirements, but also for the future expansion of traffic provides a convenient ( will only replace the standard valve body parts).