FM Approved Haz-Safe Buildings Blast Rated Wall

Steel frame members, roofing and floor channels clad with 10 gauge wall, roof and floor plate are all continuously welded. Exposed 2" square x 3/16" thick tubular steel vertical members up to 8' high on 24" centers clad with 10 gauge steel plate have a 120 lbs. per square foot rating. FM approved and tested 4' wide x 8' long explosion relief panel has 30 ft. per square foot of clear opening and constructed to exceed NFPA 68.

Haz-Safe Building's proven approach to custom engineered pre-manufactured rooms, enclosures and buildings provide superior blast rated performance as well as practical operation and aesthetic considerations. Basic explosion resistant construction requires the following elements, some or all of which Haz-Safe can provides.

a. Two methods of blast rated construction techniques have Factory Mutual (FM) approval up to 16' tall, floor-to-ceiling. By combining methods, approval is available beyond 16' high. Factory Mutual’s Class Number 6049 Approved Standard for Flammable Liquid Storage Buildings paragraph 4.2.1.B says the blast strength of the building is determined in occordance to FM Global Property Loss Prevention Sheet 1-44, Damage Limiting Construction. The results are similar to the calculations in NFPA 68.

b. All Factory Mutual Approved buildings with Damage Limiting Construction are required to have explosion relief. Haz-safe Building’s policy in regard to number of explosion relief panels is to use the highest pounds per square foot allowed by the 1-44 data sheets which is 215 lbs.sq.ft. This permits Haz-safe to use the least required number of explosion relief panels. The theory being the stronger structure requires less relief (See graphics below). Haz-safe provides patented bottom hinged, up to 8’ wide x 4’ high explosion relief panels that have been laboratory tested and approved by FM.

c. When hazmat building is within 50’ of any other structure or facility on site, Haz-safe recommends a blast shaft installed over exterior relief openings circumventing International Fire Code’s paragraph 911.1. 6. It is clear on this saying “…when venting a deflagration shall discharge directly to the exterior of the building where an unoccupied space not less than 50’ in width is provided between the exterior walls of the building and the property line”. Haz-safe patented blast shaft design was inspired by BOCA Code paragraph 417.5.1.1.2 saying “Explosion venting …through specially designed shafts to the exterior of the building”.

NOTE: All U.L. listed and FM approved components and assembled explosion relief panels are not capable of being fire rated. All hazmat rooms and buildings equipped with explosion relief panels have compromised the fire rated wall(s) and ceiling(s). A rated wall of 1, 2 or 4 hours has in fact, with explosion relief panel(s), approximately 5 to 10 minutes before extreme heat from the chemical fire destroys the panel(s) and allows fresh oxygen into the space to feed the fire. Also, fire suppression systems are designed for the protected space to be sealed in order to put out the fire. Fired rated dropdown shutters can be installed over the inside of the non-rated explosion relief panel openings and requires approval by local authority having jurisdiction.

d. Blast relief may be substituted with patented sloped floors and trenches, low level posi-ventilation tubes within the sump elevated flooring connected to dual exhaust fans on emergency power grid or generation. Requires approval by local authority having jurisdiction.

e. Haz-Safe's blast rated wall construction is designed to be as thin as possible, thereby providing either more real estate outside or more usable floor space inside. This is emphasized in the below graphics when comparing Haz-safe steel 215 lbs.sq.ft. blast rated construction with conventional concrete wall construction…

Figure A.

8' High
Haz-Safe Building's 2" x 4" x 3/16" thick tubular steel vertical members, up to 8" high, separated on 24" centers and clad with 10 gauge steel plate, has a blast rating of 215 ft.per square foot. The Haz-Safe wall is only 2-1/8" thick as compared to an 8" wide x 8' high hollow core block wall, as shown above on left. When the wall height increases, the wall needs to be strengthened with both masonry and steel in order to maintain a given blast rating. The above and below concrete construction graphic examples are based on the following considerations: These designs are to utilize (a) standard (not light) weight concrete block, (b) all cores must be fully grouted, (c) reinforcement debars are to be 60 ksi steel and should be placed on the outer edge of the cores, (d) standard horizontal bracing every other course and (e) walls have to be anchored at the roof and floor to resist the lateral blast loads. Steel designs also have to be anchored at the roof and floor to resist the lateral blast loads.

Figure B.

10' High

Figure C.

12' High

Figure D.

14' High