PRESSURE RELIEF VENTING IN CO2 SYSTEM
PRESSURE RELIEF VENTING IN CO2 SYSTEM
(OP)
Hi all,
I have designed a CO2 protection for a little electrical room (4m x 4 m x 4m). Now I would like to size the free venting area of the pressure relief venting. In order to do that I have followed the NFPA 12 requirements, using the formula:
X= 239*Q/radq(P)
Where Q= is the flow rate, in this case 22 kg/min
p = the allowable strenght of enclosure, i.e. 1,2 KPa
X =free venting area (mm^2)
Since the result is almost 0,005 m^2 I would like to ask if in this case the pressure relief venting could be avoided.
I have designed a CO2 protection for a little electrical room (4m x 4 m x 4m). Now I would like to size the free venting area of the pressure relief venting. In order to do that I have followed the NFPA 12 requirements, using the formula:
X= 239*Q/radq(P)
Where Q= is the flow rate, in this case 22 kg/min
p = the allowable strenght of enclosure, i.e. 1,2 KPa
X =free venting area (mm^2)
Since the result is almost 0,005 m^2 I would like to ask if in this case the pressure relief venting could be avoided.





RE: PRESSURE RELIEF VENTING IN CO2 SYSTEM
Regards,
DM
"Real world Knowledge isn't dropped from a parachute in the sky but rather acquired in tiny increments from a variety of sources including panic and curiosity."
RE: PRESSURE RELIEF VENTING IN CO2 SYSTEM
thank you very much for the answer. It is a concrete structure with masonry brick. I found this value of allowable strength in the NFPA 12 Table A.5.6.2.
Which is the limit value of m2 that can tell me if I need a pressure relief venting or not? Because obviously if you use this formula (X= 239*Q/radq(P)), you always obtain a number.
thanks
RE: PRESSURE RELIEF VENTING IN CO2 SYSTEM
RE: PRESSURE RELIEF VENTING IN CO2 SYSTEM
Good question. It should be the square root of P (wall strength in kPa). The equation can be found in NFPA 12, 2015 edition, section 5.6.2.2
The math does works however.
Regards,
DM
"Real world Knowledge isn't dropped from a parachute in the sky but rather acquired in tiny increments from a variety of sources including panic and curiosity."
RE: PRESSURE RELIEF VENTING IN CO2 SYSTEM