How to determine the diameter and wall thickness of pressure pipelines

1. Determination of the pipe inner diameter: Generally, material balance, energy balance, and equipment calculations are carried out based on the production scale to initially determine the material flow rate, from which the pipe inner diameter is then calculated； Furthermore, in accordance with the relevant standard GB/T 1047-2005 \"Definitions and Selection of Pipe Components – DN (Nominal Size)\", the nominal diameter DN of the pipe is determined based on the principle of priority selection. The wall thickness of the pipe is then determined according to its nominal pressure class. 3. The commonly used standards include: GB50316 \"Code for Design of Industrial Metal Piping\", GB20801-2006 \"Code for Pressure Piping – Industrial Piping\", GB50236 \"Code for Construction and Acceptance of Industrial Metal Piping Projects\", SH3501 \"Code for Construction and Acceptance of Piping Projects for Toxic and Flammable Media in Petrochemical Industries\", etc. For reference!

Thank you very much. It would be best if you could give an example to illustrate this. 2# clguan

Hehe, generally it's necessary to refer to pipeline standards

Clguan’s answer is already comprehensive and accurate. First, it’s necessary to determine the medium being transported; thereafter, the appropriate pipe material can be selected. The operating pressure and temperature also need to be taken into account to choose the right standard series of pipes – whether they are suitable for transporting fluids at low pressure, high pressure, or at low temperatures. Based on these pipe standards, appropriate formulas can be used to calculate the wall thickness of the pipes. Corrosion allowance must also be considered. The pipe diameter is determined based on the flow rate of the medium being transported; it’s first necessary to determine the optimal flow rate for that medium, which can be found in many manuals. After that, calculations can be carried out using the relevant formulas

It depends on the industry you are in; each industry has its own regulations and standards, which include formulas for calculating diameter and wall thickness. Some are calculated based on the outer diameter, while others are based on the inner diameter. Some take into account corrosion allowance and negative wall thickness tolerances, whereas others do not.

Generally, the pipe diameter is first calculated based on the material flow rate, and then the corresponding wall thickness is determined from standards using that diameter; of course, the pressure applied to the pipeline also needs to be taken into account when determining the wall thickness!

Everyone’s answers were really varied, but none of them were what the original poster wanted to hear. The determination of the diameter and wall thickness of pressure pipes is generally based on pipe grade tables. Reference can be made to the manual \"Pipelines and Fittings in Petrochemical Plants\", which contains pipe grade tables for various operating conditions. It is also possible to carry out calculations using formulas, but the values obtained through such calculations are usually smaller than those listed in the grade tables.

For the calculation of the diameter of pipes for incompressible fluids, reference can be made to the Quick Reference Manual for Petrochemical Pipeline Installation. The Mach number is determined based on the economic flow velocity; thereafter, the mass flow rate is calculated using the relationship between the Mach number and the mass flow rate. Finally, the pipe diameter can be determined using the appropriate formula. For more details, please refer to the relevant sections in that manual

For incompressible fluids: it can be calculated directly using the reference manual for the installation design of petrochemical pipelines