Hardening technology of hard seal pneumatic ball valve and modified design of seal seat The balls of pneumatic ball valves are generally machined with 1Cr18Ni9Ti and 2Cr13. Their surface hardness differs by about HB217, which is not only easy to be damaged in working conditions, but also easy to be damaged during assembly or testing. We have used the method of supercooled extrusion to improve its surface hardness, and also used the method of gas liquid nitriding, chromium plating, amorphous nickel phosphorus plating, etc., but the effect and benefit are not ideal. Since last year, we have used the solid chromizing process for experiments. After one year of practical tests, the effect is very good. After chromizing, the surface hardness of 2Cr13 and 1Cr18Ni9Ti is over HV1000 degrees. After chromizing, the surface chromium content of carbon steel ball is up to 60-80 percent. Through the hanging piece experiment of the research institute, its corrosion resistance in seawater, nitric acid, acetic acid and other media exceeds that of 1Cr18Ni9Ti and 2Cr13 without chromizing. After the trial operation of 50 sets of Q41F-16C DN50 pneumatic ball valves, our factory has received good feedback from users. Our factory has determined to fully use them in cast iron and cast steel pneumatic ball valves to replace the original 2Cr13 extremely low manufacturing ball valves and gradually expand them to stainless steel pneumatic ball valves to achieve the goal of both improving quality and reducing cost.

Five Elements of Pneumatic Butterfly Valve Selection
Rubber and Plastic Products Co., Ltd. told us about the five elements of pneumatic butterfly valve selection and the knowledge points about the classification of stainless steel pneumatic butterfly valves (1) the nominal diameter of the size hose. Xingda informed us to select the connector type (mainly flange connection, thread connection, quick connector connection), the size of the pneumatic butterfly valve, and the length of the hose.
(2) Xingda introduced the pressure demand based on the practical working pressure of the hose, and then inquired about the nominal diameter and pressure gauge of the corrugated pneumatic butterfly valve. Only then could it decide whether to use the stainless steel mesh type pneumatic butterfly valve.
(3) For the chemical properties of the medium recommended in the medium hose, we Xingda determine the material of each part of the hose according to the corrosion resistance of the hose material.
(4) The working temperature and range of the medium in the temperature hose; Ambient temperature when the hose is working. In case of high temperature, it is necessary to confirm the pressure after temperature correction according to the temperature correction coefficient of working pressure under high temperature of pneumatic butterfly valve, so as to ensure the correct pressure level is selected.
(5) State Xingda informed us that according to the state of hose application, referring to the correct application and installation method of pneumatic butterfly valve and the optimal length of high-pressure hose for settlement compensation, the length calculation of various motion states of hose, the minimum bending times and minimum bending radius of hose and other factors, the hose length should be correctly selected and correctly installed.