Today, we are going to discuss the "Piping Thickness Schedule (Sch) Calculation MethodHere is a note about "The
A piping schedule, or Schedule, is a standard for the thickness (wall thickness) of a pipe. As shown in the table above, schedules are represented by numbers, such as Sch40, Sch80, Sch160, etc,The larger the schedule number, the thicker the wall thickness of the piping, allowing the piping to withstand higher pressures.
Schedule (Sch)
The formula for selecting the schedule (e.g.:STPG tube）
The formula is as follows
Sch=P/S*1000
Sch: Schedule No.
P: Design pressure [MPa]
S: Allowable tensile stress of piping at design temperature [N/mm2].
The tensile strength of the piping is not the value specified in the material specification, but the allowable stress at different temperatures of the piping.
STPG370-S: Allowable tensile stress from -10°C to 350°C = 92 N/mm2
STPG370-W: Allowable tensile stress from -10°C to 350°C = 78 N/mm2
STPG410-S: Allowable tensile stress from -10°C to 325°C = 103 N/mm2 326 to 350°C = 102 N/mm2
STPG410-W: Allowable tensile stress from -10°C to 325°C = 88 N/mm2 326 to 350°C = 87 N/mm2
The following is a list of the items that can be used for pressure vessels. For details, please refer to JIS B 8265 (Structure of pressure vessels - general matters).
Example of calculation to select a schedule
Example (6 MPa pressure at 50°C,STPG370-S(When designing with)
Since 6/92*1000 = 65.2 SchSch 80 or higher should be selected.
That's it.