Transformer Blast Wall
Transformer Blast Wall
(OP)
I am currently designing a foundation / blast wall system for an electrical transformer ( greater then 5,000 gal). I have the separation and line of sight requirements to determine the height of the wall but looking at FM Global, IEEE and NFPA, I do not find a way to determine the design blast force to apply to the wall.
Does anyone have experience or references on how to determine the blast force on a wall a certain distance from a fuel source? or are there are code provisions on how to determine the design loads required on a blast wall for a transformer?
Does anyone have experience or references on how to determine the blast force on a wall a certain distance from a fuel source? or are there are code provisions on how to determine the design loads required on a blast wall for a transformer?






RE: Transformer Blast Wall
The NFPA 850 Standard states the height and the clearance for the Fire Wall. The Fire Wall shall withstand 4 h fire exposure.
No indications about blast pressure, indeed. My opinion is the Fire Wall should resist the local conditions. For instance, in hurricane region for a maximum of 200 mph speed, wind the pressure will be 90 psi [usually is less than 10 psi].
The effort due to earthquake is also a criterion.
The old Code of Federal Regulation [CFR30], based on investigation of underground coal mine stated 20 psi for a seal structure [in case of methane-air mixed explosion]
The new Code could state 130 psi -see the draft:
http://www
The experiment described in this Draft was conducted in a closed enclosure. In the substation outdoor case it is only a confine area [no roof] so I think 20 psi blast wave pressure will be fair.