D = 18.8 (Q / V) 1 / 2D is the inner diameter of the pipe, MMD is the inner diameter of the pipe, MMQ is the medium volume flow, m3 / h ˇ Is the average flow rate of medium, M / s, where the flow rate of compressed gas is 10-15m / s. calculated, d = 48.5mm, and the actual value is 57 × 3.5 pipeline can be explained. The above calculation is under normal temperature, and it is appropriate to separately calculate the high-temperature gas. The above Q refers to the actual gas flow, which shall be converted into the actual gas flow under the index condition. From PV = NRT formula, it can be deduced that the design of air pressure pipeline belongs to the category of pressure pipeline (the pressure is greater than 0.1MPa and the pipe diameter is greater than 25mm).

There are many types of compressed air pipes in Dalian, including galvanized pipes, carbon steel pipes, stainless steel pipes, PPR pipes, new aluminum alloy pipes, etc. the traditional galvanized pipes will rust inside after a period of time, which will cause great damage to terminal equipment. The cost of stainless steel pipes is too high. The PPR pipes are cheap, but the safety is poor. The best choice is aluminum alloy quick cannula, which is safe and corrosion-resistant. The installation cost is not high, and the installation is convenient, simple and beautiful.

The connection of pressure pipes shall be mainly by welding. Valves, equipment interfaces and pipes with special requirements shall be connected by flanges. For the selection of valves, it is recommended to first understand the type, function, structural form, connecting valve body material, etc. Stop valves and ball valves can be used for compressed air pipes. Stop valves are used for large pipe diameters, and ball valves are used for small pipe types and diameters.