Tankarator
Mechanical
Hey all,
I am a relatively new API 653 inspector (originally certified in 2021) and have recently been delving into the requirements for emergency venting for tanks that are inspected under API 653. Many of the tanks I have inspected are old (circa 1960) and lack original design or fabrication records. Additionally, many of these tanks are less than 50' in diameter and either do not possess any emergency relief devices or have something small such as a 10" Morrison Brother Figure 244. As such, it is difficult to determine whether these designs were "code compliant" at the time of construction.
Regardless, under the current edition of API 653 (2020), section 9.12.1.1 states that, "Roof repairs involving tank venting shall be made such that normal and emergency venting meet the requirements of API 650, Section 5.8.5".
Following through with API 650 section 5.8.5 involves significant work including determining tank roof frangibility, field verifying tank design, estimating material weights, calculating allowable pressures in accordance with Appendix F, calculating appropriate venting capacities in accordance with API 2000, etc.
Is it the intent of API 653 that all existing tanks inspected under the standard comply with the current emergency venting requirements of API 650 and API 2000?
I cannot imagine that that is the intended interpretation, but I also cannot find a caveat that would allow you to interpret it differently, especially for tanks that do not possess dedicated emergency relief devices and whose frangibility is dubious.
These tanks have been in service for 80+ years without issue, so I don't want to be the guy that makes them add a stuff for no reason. But, if they are non-compliant then they are non-compliant.
Am I incorrect or missing something in my interpretation?
Any input would be appreciated.
Thanks,
I am a relatively new API 653 inspector (originally certified in 2021) and have recently been delving into the requirements for emergency venting for tanks that are inspected under API 653. Many of the tanks I have inspected are old (circa 1960) and lack original design or fabrication records. Additionally, many of these tanks are less than 50' in diameter and either do not possess any emergency relief devices or have something small such as a 10" Morrison Brother Figure 244. As such, it is difficult to determine whether these designs were "code compliant" at the time of construction.
Regardless, under the current edition of API 653 (2020), section 9.12.1.1 states that, "Roof repairs involving tank venting shall be made such that normal and emergency venting meet the requirements of API 650, Section 5.8.5".
Following through with API 650 section 5.8.5 involves significant work including determining tank roof frangibility, field verifying tank design, estimating material weights, calculating allowable pressures in accordance with Appendix F, calculating appropriate venting capacities in accordance with API 2000, etc.
Is it the intent of API 653 that all existing tanks inspected under the standard comply with the current emergency venting requirements of API 650 and API 2000?
I cannot imagine that that is the intended interpretation, but I also cannot find a caveat that would allow you to interpret it differently, especially for tanks that do not possess dedicated emergency relief devices and whose frangibility is dubious.
These tanks have been in service for 80+ years without issue, so I don't want to be the guy that makes them add a stuff for no reason. But, if they are non-compliant then they are non-compliant.
Am I incorrect or missing something in my interpretation?
Any input would be appreciated.
Thanks,