How to choose correct types for the control valve in the paper industry ,let's introduce the control valve types selection.
In the paper industry, the choice of control valve is obviously different from other industries.Papermaking process is divided into two parts: pulping and papermaking.The pulping process is to make the raw materials with rich fiber such as this material into pulp that can be made into pulp through such processes as material preparation, steaming, washing, screening, bleaching and so on. The pulping process sent by the pulping department will be mixed with pulp, and the finished paper will be produced after such processes as flow delivery, pressing, drying and coiling.In addition, the alkali recovery department recovered the alkali liquor from the black liquor after pulping for reuse.The waste water treatment department is to treat the waste water after papermaking, so that it can reach the relevant national emission standards, and every process of papermaking production mentioned above need control valve to control it. 
 
For the paper making industry, the main media in production are: slurry, steam, water, sewage and black liquor, etc. In these media, the slurry in the bleaching section contains a small amount of chlorine ion, and the black liquor in the washing and screening and alkali recovery department contains alkali, other media are less corrosive.In the whole production process, the pressure of the above medium in the pipeline and the container is generally no more than 1.6MPa.All medium steam temperature, the highest saturation temperature is 203 ℃. 
It can be seen from the above analysis of medium performance that the control valve in production does not need to consider the factors of high temperature, high pressure , strong corrosion and explosion, etc., and complex situations such as flash of liquid, obstruction and noise caused by high pressure difference can be omitted in the selection and calculation.These facilitate the choice of control valve. 
Single seat, double seat and sleeve control valve widely used in other industries which are also applicable to water, steam and gas control in paper industry. As for the control of pulp and black liquid, rotary v-type regulating ball valve, o-type regulating ball valve and regulating butterfly  valve are widely used, which is the characteristic of paper industry.