Antifreexe systems for storage
Antifreexe systems for storage
(OP)
Hi,
FM Global 2-0 Section 2.4.7.1 says that a 30% solution propylene glycol antifreeze system is acceptable if the ambient temperature of the protected area is maintained at or above 25°F (-4°C), as well as at or below 200°F (95°C) at all times.
Are there limitations to this (aside from the temperature ranges) or is it a viable option for any wet system design with using FM Approved piping/heads if the protected area is between 25°F and 200°F as noted. I would assume that a premixed 30% propylene glycol solution would need to be used.
I know there was a concern in the past with using them with ESFR heads becuase of combustibility of some antifreeze solutions (primarily greater than 50% mixes), but I wouldn't expect a 30% propylene glycol and 70% water solution to even have a fire point.
Thanks for your time.
Wally
FM Global 2-0 Section 2.4.7.1 says that a 30% solution propylene glycol antifreeze system is acceptable if the ambient temperature of the protected area is maintained at or above 25°F (-4°C), as well as at or below 200°F (95°C) at all times.
Are there limitations to this (aside from the temperature ranges) or is it a viable option for any wet system design with using FM Approved piping/heads if the protected area is between 25°F and 200°F as noted. I would assume that a premixed 30% propylene glycol solution would need to be used.
I know there was a concern in the past with using them with ESFR heads becuase of combustibility of some antifreeze solutions (primarily greater than 50% mixes), but I wouldn't expect a 30% propylene glycol and 70% water solution to even have a fire point.
Thanks for your time.
Wally





RE: Antifreexe systems for storage
If so how many sq ft??
Also you may need to calculate the Darcy–Weisbach formula depending I what edition of 13 you design to
RE: Antifreexe systems for storage
To your question of what size, I'm looking at it for a system that's about 25k sq.ft. But that was really my question... are there limitations (other than those for wet pipe systems)? Using FM 8-9 (a national recognized standard) as an alternative to 13, it appears to allow (per 2-0 2.4.7.1) the 30% or less propylene glycol (PG) systems as long as the ambient temp is between 25 and 200 deg F. Seems perfect for a 30-35 deg cooler. I would like to use it with K-25 quick respose heads using a design from 8-9 and I can't find any reason that this is not allowed. As to the Darcy Weisbach method, I'm not sure that there would be much difference between it and HW at the proposed temp and only 30% PG, but I agree that calcs should at least be run to determine that.
Thanks for your time.
Wally
RE: Antifreexe systems for storage
RE: Antifreexe systems for storage
It is not an FM insured but I occasionally use FM standards as an alternative to NFPA 13 per the equivalency clause (section 1.5). Funny how now a days some of the FM standards are more friendly than NFPA - used to always be the opposite. I did contact the local FM office yesterday for a clarification of their standard and the initial response was that AF systems could not be used for much other than loading docks, canopies, etc. (<20 heads) - no storage and no large systems. I don't read it this way except for where you have temps less than 25 deg F that require a higher concentration of antifreeze. I have gone back to them to try to clarify - I don't think they see many of these. I think there has a been a reluctance to use AF systems in the past for large systems since PG is a combustible liquid in higher concentrations and it can also become extremely viscous at cold temperatures. There is a small temperature window in which these are applicable. Lots of questions... I appreciate your response and if I get a different ruling from FM, I will provide to the board.
Wally
RE: Antifreexe systems for storage
RE: Antifreexe systems for storage
RE: Antifreexe systems for storage
RE: Antifreexe systems for storage