Determination of pipe wall thickness
Thread Content
I would like to ask the experts: For a steam pipeline with a design pressure of 6.4 MPa, a design temperature of 480°C, and a diameter of DN600, what is an appropriate wall thickness? If expressed by the pipe schedule number, should it be SCH40 or SCH60?
Design temperature: 480°C, design pressure: 6.4 MPa. Assuming the pipe is a No. 20 carbon steel pipe, the allowable stress at 475 degrees is 45 MPa. Substitute the initially selected wall thickness into Barlow’s formula; Barlow’s formula is SCH=P/S*1000. SCH=6.4/45*1000=142; the wall thickness calculated using the Barlow formula is a conservative value. Refer to ASME B36.10M-2004; rounding gives SCH=140, resulting in an outer diameter of 610 mm and a wall thickness of 52.37 mm
Dare I answer? Dare you accept it? ! For this requirement, look for manufacturers of high-pressure boilers or Class A design institutes; carbon steel cannot be used for steam at such high temperatures
The material is 12Gr1MoVG
For these temperature and pressure conditions, it’s better to calculate using the pipe wall thickness formula
At these temperature and pressure levels, carbon steel cannot be considered. Consult the design firm; they have the qualifications to provide professional answers.
Select pipeline material based on material usage restrictions； Calculate the thickness again. Critical steam boilers are already a highly mature technology. There is no difficulty in this question.
The data from the design institute might be more accurate