Circular Duct thickness calculation

Can we use ASME B31.3 thickness calculation formula for calculating thickness of circular duct lined with refractory material? Does refractory lining have any impact on thickness calculation?

Hi Rajeev,

I don't see why not, and usually refractory lining is not involved in the pipe wall calculation.

Bryan
Hexagon CADWorx & Analysis Solutions

Thanks for your response Mr Bryan.

Also can you guide me to understand What temperature shall we consider for allowable stress to be used in thickness calculation. Fluid temperature or surface film temperature which will be very less compared to fluid temperature?

Do you really consider that pressure/metal temperature is the load that drives your circular duct calculation?

its a circular duct used for transferring gases/air from fan to blast stove and from blast stove to chimney in a steel plant. Client has asked to used ASME B31.3 for calculation. So I believe, we can use pressure thickness calculation formula provided in the code. Please correct me if I am wrong.

You can use that formula, however you still need to consider a lot of B31.3 provisions that, in the end, would reveal that using thickness based on pressure is not relevant. For example, in your case 2800mm dia, sustain, local stress, etc. are probably more restrictive in calculation than pressure. But in the end, it depends on the design pressure you/ your Client assumed.

I suggest you to consider Round Industrial Duct Construction Standard, ANSI/SMACNA 005-2013, which has also calculation guidance.

BR.