Blast resistant doors are designed to protect property and people against the problems and dangers created by an explosion, pressure leak, fire, blasts, radiation or theft. Blast doors are more commonly associated with government buildings, chemical storage facilities, military buildings, and many different refineries. Earlier versions of blast door technology were made very popular in the mid-1950s, because of the cold war era fears. Blast doors still remain a very popular structure and its technology is rapidly growing.
Blast Door Engineering
Blast doors are an engineering feat as they involve pressure ratings, basic math, engineering construction knowledge and standards. Pressure ratings are specified by certified engineers who factor in trajectory theories, distance and blast force equations and much more. Pounds per square inch or PSI and pounds per square feet or PSF determines the blast radius and assembly. Blast doors fall into 3 categories based off PSI rating. A PSI rating of 6 or higher is called a “high-range” blast door, PSI ratings of 4 to 5 are called “medium range” blast doors and a PSI rating of 1 to 3 is considered a “low-range” blast door assembly.
Blast Door Ratings
A blast door frame and its hardware components and parts are also factored by PSI ratings. Generally, the exterior surface of a blast door is manufactured from cold-rolled steel sheets or aluminum. Its interior surface is comprised of either “hat sections” or “structural tubing,” which is thick carbon steel. Hat sections are actually shaped like a hat and structural tubing is shaped like a square or a rectangle design. To determine which interior surface is used, will depend on the size of the door, the PSI rating required, and the blast specifications needed. The blast door frame way is designed to transfer the blast pressure to the walls and the low to medium blast rated frames are engineered to be anchored to tube studs, blocks, or concrete. Higher blast doors, however, are best anchored to embedded steel channels or installed within the walls when the concrete is being poured with anchor bars.
Aesthetics of Blast Doors
Blast doors can be made in any shape without the pressure effects changing. Some designs used, include concave, convex, single doors, pair, sliders, swinging, and vertical lifts. As impervious as blast door materials are, they can still be veneered to match their environments, especially in public locations like banks, courthouses, embassies, offices, or retail settings. High blast door ratings can use both custom designed hardware, but off-the-shelf hardware can also be the basics for modifying it to be used with low or medium blast door ratings.
Blast Door Tests
There is a tricky, almost complicated method to actually test blast doors. Their testing and certification is presently being studied to create a standard. However, the only “shock tube testing” process which uses controlled level airbursts to test the blast door’s rating, is still an expensive method, therefore, blast door analysis are based on what computation of blast door engineers.
The Best Blast Door Manufacturers in Texas
Carefully choosing a blast door manufacturer is vitally important as quality is a requirement. That is why industries use the services of the Armortex Company which has been manufacturing bullet, blast, and forced entry resistant products for over 30 years. Their product line includes Armortex® brand fiberglass composite panels, glass and containment glazing, fixed windows and transaction windows, pass-thru transaction equipment (drawers, hoppers, dip trays), speakers, gun ports, gun lockers and man traps.