tank emergency venting requirement
tank emergency venting requirement
(OP)
Hi all,
Pardon me with this trivial question but I'm working away from my office and have no access to reference material and I need a quick answer. I hope someone can help out here.
I just need a confirmation if I need a tank emergency relief valve on a storage tank (APi650)with frangible roof joint. I know API2000 section 4.3 specified this is optional but I think I recall NFPA 30 forces us to still put one on (or several depending on capacity) for fire case. Can someone with access to NFPA 30 or expert knowledge on tank venting confirm this for me? Thanks for reading this.
Pardon me with this trivial question but I'm working away from my office and have no access to reference material and I need a quick answer. I hope someone can help out here.
I just need a confirmation if I need a tank emergency relief valve on a storage tank (APi650)with frangible roof joint. I know API2000 section 4.3 specified this is optional but I think I recall NFPA 30 forces us to still put one on (or several depending on capacity) for fire case. Can someone with access to NFPA 30 or expert knowledge on tank venting confirm this for me? Thanks for reading this.





RE: tank emergency venting requirement
Joe Tank
RE: tank emergency venting requirement
See page 30-14 on this document... http://
Chapter 22.6 on the above document corresponds to Chapter 22.7 of the 2008 Edition of NFPA 30.
As I understand it, a frangible roof joint is considered an "emergency relief venting construction".
RE: tank emergency venting requirement
Doct9960, Yes, I am aware that the frangible joint is considered an emergency relief "device". That's why I mentioned API2000 give us the option to put on an ERV when the roof in frangible. What I'm not sure of is what NFPA 30 dictates us to do. I remembered I read long time ago that NFPA 30 insists on a ERV for fire case even if the roof is frangible, but I'm not sure since its been 10 years ago. Heck of a time to forget to bring along my repository of knowledge in my portable drive.
Thanks guys and good night.
RE: tank emergency venting requirement
RE: tank emergency venting requirement
API STD 2000 paragraph 4.3.3.1 gives you the option to add emergency vents on frangible roof joints. The purpose of those nonmandatory vents is to avoid failure of the "frangible" joint.
RE: tank emergency venting requirement
My two cents....
As a mater of practicality, I suggest that the emergency device always be installed and that the reliance on a "frangible roof joint" to meet code requirements be discouraged.
As we all know, the shell to bottom welded joint is the most highly stressed one in the tank and also in a location most prone to corrosion. Whether that corroded joint or the "frangible roof joint" would be first to fail in an accident is up to anyones guess.
A few years back, there were seminars concerning the actual effectiveness of this type of roof joint on smaller diameter tanks.
The preferred device, as I understand, is always the manway mounted spring relief device. You do, of course, need a roof mounted manway.
My recollections only....
-MJC
RE: tank emergency venting requirement
RE: tank emergency venting requirement