Floating Roof Venting

[Civilpetro]

The foreword in API 2000 says that "This standard does not apply to external floating roof tanks or free vented internal floating roof tanks"

If I have an external floating roof, how do I size the P/V valve and what parameters do I need use If I can't apply API2000? Thanks.

 

[rmw]

What exactly is your definition of an external floater?

rmw

 

[Civilpetro]

Im sorry, I meant Internal Floating Roof. A tank with a fixed roof and a floater inside.

 

[IFRs]

If this is an API 650 tank, venting for internal floating roofs needs to comply with API 650 Appendix H. Appendix H gives you two choices: (1) add circulation vents in which case API 2000 does not apply or (2) inert the vapor space in which case API 2000 does need to be checked.