Explosion Relief Panels:

Explosion Relief Panels on Haz-Safe Buildings:

Exceeds NFPA 68 Code, bottom hinged, 15 to 30 lbs.sq.ft. adjustable magnetic release,  capable of being reset after, testing, wind and blast openings, shock absorbing cable tethered, R-9 insulated, all aluminum, FM tested and approved, 8’ wide x 4’ high explosion relief panel. Dropdown shutter (16' long gray box) fire rates two explosion relief panels. Anti-projectile security screen covers inside panel openings. Two security magnet contacts signal alarm to remote central station when panels open. Top hinged panels direct blast effects downward. These patented panels are the only panels ever tested and approved by Factory mutual.  Haz-safe Buildings’ version is bottom hinged to redirect blast effects upward. (Click here to see FM test video)

Haz-safe Buildings’ proven approach to custom engineered explosion relief panels and their applications are dependent on the following code requirements, all of which Haz-safe can provide.

a. NFPA 68 has specific requirements as to the construction and limitations on dimensions ( up to 8’ x 4’) and weight (not to exceed 2.5 lbs.sq.ft. ). Reason being the panel has to open as quickly as possible. Therefore must be of light weight construction and limited in size to overcome inertia and drag.

b. All Factory Mutual 6049 Standard 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 FM’s 1-44 Date Sheet 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. 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. Factory Mutual’s instructions to all hazmat building manufactures states, “This building incorporates damage limiting construction (explosion relief) panels. These panels are not fire rated. This may compromise the fire rating on any wall that incorporates such panels. This requires the end user to give careful consideration on where this structure is located and how it is oriented on the property. The structure needs to be oriented such that the fire walls that do not contain these panels are adjacent to other structures that need to be protected from a fire exposure…” Conversely, walls containing the explosion relief panels must be oriented such that if a fire occurs, the direction of the venting is away from the main building or other occupied areas. Here the threat is radiating out the opening when the relief panels are destroyed in minutes by up to 2,000 degrees fire fueled by flammable and combustible chemical liquids and oxygen rushing in the opening.

d. UL Listed and FM Approved fire rated dropdown shutters can be installed over the inside of the non-rated explosion relief panel openings which solves the problem of explosion relief panels not being fire rated. A fusible link (165 degrees) releases a steel curtain to seal the openings before the relief panels are destroyed (requires approval by local authority having jurisdiction). See dropdown shutters pictured in the middle photograph above.

e. Blast shafts also can dramatically reduce the effects of radiant heat emanating from explosion relief openings when applied over the outside of the openings (requires approval by local authority having jurisdiction).

Explosion Relief Panels on Haz-safe Building Damage Limiting Construction:

INSIDE: Explosion relief panel back wall of the two story high room of the second and third level modules. The gray horizontal beams are temporary for shipping and were removed. Also the brown composite board was replaced by a vent louver as seen in photo on right…

OUTSIDE: (24) 8’ W x 4’ high and (12) 4’ square explosion relief panels fill the back wall of three story (three shipping module stacked on top of each other)  building. Factory Mutual’s 6049 Standard’s use of FM 1-44 and or the NFPA 68 calculation will take up all of and some times more than the back wall of a Haz-safe building. Walls are 215 lbs.sq.ft blast and 4 hour fire rated.

Explosion Relief Panels on Conventional Damage Limiting Construction:

Exterior view of an explosion relief framed assembly with six 4’ high x 5’ wide relief panels side to side and stacked on top of each other. These assemblies are costumed sized to fit the opening in existing concrete walls. It could have had the same number of arranged panels that were 4’ high x 8’ wide with a frame for a larger hole.  Over every row of panels is a 2” angled rain drip edge. Assembly is installed utilizing welded in place crane lifting lugs. Interior view shows a ¼" thick steel flange surrounding the entire perimeter of the frame to be utilized for bolting to the concrete wall. The tubular steel frame surrounding each panel can withstand a minimum of 215 lbs.sq.ft. blast pressure and can be dimensioned to match the depth of the concrete wall. Options include anti-projectile/intruder security screens and an interior angular steel frame to cover caulk/foam filled space between assembly frame and concrete opening.
BEFORE: Existing 13' wide x 6' high "homemade" explosion relief vent held in place with FM approved fasteners that can be utilized with any dimensioned metal or FRP panels. In this case the fasteners uses washers designed to collapse upon impact of an explosion which do not let go simultaneously so the panel is misshapen or ripped into shrapnel as it tears away from the opening in the wall. User concerned with air and fume infiltration getting out and moisture getting in... AFTER: Installation of Haz-safe Blast Relief Wall Assembly equipped with (4) custom 6' 3" wide x 2' 9" high bottom hinged, single adjustable setting magnetic release, cable tethered, aluminum relief panels. Panels are factory pre-installed within a ¼" thick tubular steel frame and shipped to site for installation in existing wall opening.
Inside of the room shows how tight the seal is and the bolts inserted through the ¼" thick 8" deep assembly frame into the existing poured concrete wall. There is an optional stainless steel angular "picture frame" frame trim that can cover the foam sealing material. Close up of the fastening and the sealing of the Haz-safe Blast relief Assembly on outside wall. Notice the rain drip edge. Should a fire occur in the room and melt away the relief panel or an explosion start a fire after the relief panels open, the existing buildings roof overhang will catch fire from the flames coming out of the wall opening. A blast shaft installed over the exterior of the relief panels would protect the roof overhang from catching fire.