Relief requirements from steam tracing

[sub8582]

Hi guys,

I am working on re-evaluating the relief requirements for a pressure vessel. The vessel has steam tracing (by 50# steam) per P&ID; i dont have any other information. The fluid residing in the vessel can vaporize when blocked in and steam tracing continues. Is there any conservative way to calculate the relief rquirements from steam tracing when vessel is blocked in? Also could you tell me what are the code requirements for a vessel or pipe to be steam traced. The code requirements i meant here is for pressure relief requirements. Thanks for your help.

 

[Chance17]

The steam tracing represents heat input (btu/hr) and temperature.
At the temperature of the condensing steam, you need to determine if the internal fluid will boil at relieving conditions.
If true, the required safety valve flow is steam trace btu/hr divided by fluid latent heat at relieving conditions.

For small vessels the steam tracing can represent considerable internal heating.
As vessels get larger, the steam tracing merely prevents heat losses to ambient environment