jimmyhutmacher
Mechanical
I'm looking at designing emergency venting for two different tanks, one for asphalt/bitumen storage and one for used motor oil storage. The design spec for both tanks is API 650 which states that all tanks require a form of emergency venting: tank frangibility or pressure relief devices per API 2000.
However, NFPA 30 states that tanks storing Class IIIB liquids that are larger 12,000 gallons and are not within the diked area or the drainage path of tanks storing Class I or Class II liquids do not need to consider emergency venting. And both tanks meet all criteria for this exemption.
Question is, would we be required to meet API 650 rules or could we use the NFPA 30 exemption? Or maybe a better question, is there a standard practice in the industry regarding emergency venting for Class IIIB liquids or more specifically, asphalt/bitumen or used motor oil?
Part of the issue with providing emergency venting is that I can't find definitive numbers for the Latent Heat of Vaporization and Molecular Mass of Vapor for either liquids, which I need for API 2000 Equation (15). And in lieu of Equation (15), I'm not sure if it's reasonable/conservative to use the Hexane Tables 5 through 8 since I don't believe they have similar properties.
I did come across the Vetere Model for the Latent Heat of Vaporization of Pure Hydrocarbons = 4.1868*T *(9.08+4.36*log(T)+0.0068*T/M+(0.0009*T^2)/M) T = Boiling Point in Kelvin M = Molecular Mass of Liquid
Not sure if this is accurate since asphalt and used motor oil are composed of innumerous types of hydrocarbons with extreme variation in boiling points and molecular weights.
Any input would be greatly appreciated on any of the topics above. Thank you!
However, NFPA 30 states that tanks storing Class IIIB liquids that are larger 12,000 gallons and are not within the diked area or the drainage path of tanks storing Class I or Class II liquids do not need to consider emergency venting. And both tanks meet all criteria for this exemption.
Question is, would we be required to meet API 650 rules or could we use the NFPA 30 exemption? Or maybe a better question, is there a standard practice in the industry regarding emergency venting for Class IIIB liquids or more specifically, asphalt/bitumen or used motor oil?
Part of the issue with providing emergency venting is that I can't find definitive numbers for the Latent Heat of Vaporization and Molecular Mass of Vapor for either liquids, which I need for API 2000 Equation (15). And in lieu of Equation (15), I'm not sure if it's reasonable/conservative to use the Hexane Tables 5 through 8 since I don't believe they have similar properties.
I did come across the Vetere Model for the Latent Heat of Vaporization of Pure Hydrocarbons = 4.1868*T *(9.08+4.36*log(T)+0.0068*T/M+(0.0009*T^2)/M) T = Boiling Point in Kelvin M = Molecular Mass of Liquid
Not sure if this is accurate since asphalt and used motor oil are composed of innumerous types of hydrocarbons with extreme variation in boiling points and molecular weights.
Any input would be greatly appreciated on any of the topics above. Thank you!