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10531 E US Hwy 40, Independence, MO 64055

  • DEFCON Mfg


Underground Bunker Defensive Upgrades

underground bunker defensive steel plating

AR500 Steel Plate

DEFCON uses AR500 Steel plate in 3/8” and 1/2’’ in all of its Underground Bunkers – Bomb Shelter  blast doors. AR500 steel is an abrasion resistant steel plate used in high-wear applications, like mining or material handling. This steel is heat treated to exhibit through-hardening, improved forming, and welding capabilities. AR500 steel possesses excellent resistance to slide wear, rub wear and heavy wear. It can also withstand high impact stresses, even at extremely low temperatures. With its ability to withstand high impact stress, AR500 has been widely popular for its uses in body armor and ballistic plates. AR500 steel can stop many threats, including, but not limited to:

  • Pistol Calibers: .22LR, 9mm, .40 S&W, 45 ACP, 10mm, .357 Magnum, and .44 Magnum
  • Rifle Calibers: .223/5.56 (M855 62g Penetrators), 7.62×39, 7.62×51 (M80 Ball), .308 Winchester, 12 Gauge 3” Magnum 00 Buck, and 12 Gauge 1oz Slugs
  • Platforms include a variety of Handguns, Pistol Caliber Rifles, and Rifles to obtain a wide variety of velocities for a given round.

DEFCON also offers many more Defensive Upgrades 

For a Free Quote, call us at (816) 438-7171 or

underground bunker defensive blast valve

Blast Valve

As a high pressure wave from a nearby detonation passes over the shelter, the pressure travels down the pipes and into the shelter. If it is not stopped, it will destroy the air filtration equipment and injure or kill the occupants.

Directly behind this high pressure wave is negative pressure (less than atmospheric) because the atmosphere is blown outward from the center of the detonation leaving a partial vacuum. This phase of the detonation can be as dangerous as the pressure wave.

A blast valve is a heavy steel vessel that will allow regular air to flow freely, but automatically slam shut when a high pressure wave comes down the vent, in turn protecting your bunker and family. When the outside air pressure returns to normal, the blast valve automatically returns to its normally open state. This allows to air flow into your air filtration system and out of your exhaust port for normal operation, but will not allow a blast of high-pressure air to enter your underground shelter – and bring contaminants with it.

The blast valve also feature a manual lock/or ball valve to shut it in case you have malicious people outside your shelter attempting to dump water, fuel, or smoke down your ventilation pipes.

For a Free Quote, call us at (816) 438-7171 or

underground bunker defensive over pressure valve

Over Pressure Valve

This over pressure valve is a one way check valve that installs on the outflow vent pipe of your shelter. It only allows air to flow out of, not into your underground protected space. It is normally closed and will not open unless the air pressure inside the shelter is slightly greater than the outside air pressure. It opens when the air filtration system is turned on and gives a little back pressure to the air filtration system to help it create and maintain the positive pressure.

This gives the air filtration system something to push against, helping it maintain overpressure and it won’t let any contaminated air back up through the outflow pipe into your shelter.

The air filtration draws air down the intake ventilation pipe, through the intake blast valve, through the filter bank, and then expels the filtered air into the shelter at a slightly higher pressure than the air outside the shelter (positive pressure or overpressure).

This gives you true ventilation – air in through the air filtration system and out through this valve. This replenishes the oxygen and removes the carbon dioxide exhaled by the occupants.

The overpressure valve must be oriented so it points at the floor because it partially uses gravity to keep the synthetic rubber diaphragm closed. We include both wall and ceiling adapters. All joints between the overpressure valve, the adapters, and the blast valve are slip fit so they can be assembled or disassembled for cleaning or servicing without tools. It can be attached directly to the inside wall or ceiling or on a blast valve.

For a Free Quote, call us at (816) 438-7171 or

underground bunker defensive nbc filtration

NBC Filtration

Your bunker’s most critical job is protecting the air you breathe. Our systems meet military specifications from the US Army Corps of Engineers Design of Collective Protection Shelters to Resist Chemical, Biological, and Radiological (CBR) Agents, Technical Letter Number ETL 1110-3-498. Each system will be equipped with a battery back-up system in case the grid goes down. Extra replacement filters are also available for our systems. 

  • The best selling NBC air filtration system in America with thousands of installations
  • Protecting the most critical part of your shelter – the air you breath
  • Two sizes – 60 CFM for up to 12 people and 120 CFM for up to 24 people
  • Every Unit runs off of standard 120 volt AC household electricity and comes with a 12 volt battery backup power cord
  • Manual battery backup systemsrequire you to switch the power source to the battery if the grid goes down
  • Automatic battery backup systems switch to the battery without any user input

For a Free Quote, call us at (816) 438-7171 or

underground bunker defensive surveillance


Surveillance cameras are a prime example of how far security has come in the last couple of years. Depending on where you mount them, you will find that they can offer you a 360 degree level of coverage; you can even program how it pans and tilts as well. Some CCTV cameras can even be set to track motion in case of theft or vandalism, so you feel completely at ease.

Some surveillance cameras include zooming capabilities of up to 100 feet and a weather-proof design that can withstand extreme heat, modern surveillance cameras are ideal for any purpose and a must-have for your bunker. DEFCON can provide you with simple to the most advanced surveillance systems.

For a Free Quote, call us at (816) 438-7171 or

underground bunker defensive electronic access

Electronic Access

Most likely, if you are using your underground bunker, your safety is at risk. For that reason, DEFCON recommends state of the art fingerprint access control systems. Our systems are also available with a pin code access system as well, so you can get two layers of security without any extra installations. If you require a higher level of security clearance, DEFCON also installs facial recognition systems.

If you are thinking about getting our fingerprint door access control system installed, then you should note that this system will only give you access if you place your finger on the scanner. The scanner will then use your personal fingerprint image to determine whether or not you are allowed access. This alone makes it one of the most secure forms of security on the market. If you want to give other people access to the system, then all you need to do is give us a call. Once you verify your identity, we will work with you to give them access. The same applies to those who you want removed from the system. We are always here to help if you are having any problems with your device or your security system in general. It is important to us that our systems are flawless in their operation, so all you need to do is get in touch with us, and we will gladly assist you.

For a Free Quote, call us at (816) 438-7171 or

underground bunker defensive bullet proof glass

Bullet Proof Glass

DEFCON offers several high-quality options for ballistic glass and Kevlar.

Polycarbonate Security Glass

    Polycarbonate can offer Level 1 protection in just 3/4″, Level 2 at 1″, and Level 3 at 1 1/4″. Polycarbonate is great for exterior windows because of its resistance to forced entry: a sheet of polycarbonate will take an hour of beating with a sledgehammer. Polycarbonate security glass comes standard with abrasion resistant coating, which increases durability against solvents, weather, and ultra violet light. It does, however, have a noticeable tint, creating a darker interior.

Ballistic Glass-Clad Polycarbonate

    Like traditional laminated glass, glass-clad polycarbonate is challenging to fabricate into acrylic-style seamless systems. Also like polycarbonate, it suffers from poor light-transmission. However, glass-clad polycarbonate can be layered thicker and thicker to the highest-rated levels of bullet resistance, easily stopping a burst from an M16 or AK-47. It also holds up well during hurricane winds and attempted forced entry, making it a great exterior option.

Bullet Resistant Acrylic Security Glass

    Bullet Resistant Acrylic Security Glass is available uncoated or with an abrasion resistant coating, which increases durability against solvents, weather, and ultra violet light. This material consists of a single piece of solid plastic ranging from 1¼” to 1⅜” and can be drilled, routed, cut, and slotted to seamlessly integrate with the mounting hardware. Due to the seamless installation and its ability to pass light through, this option tends to be used as an interior option.

Bullet Resistant Fiberglass

    Also known as Opaque Armor or bullet-resistant DuPont™ Kevlar® fiber, Bullet Resistant Fiberglass is a layered, reinforced structural polyester laminate (fiberglass) that offers unique bulletproof characteristics. Press molded between steel plates at high pressure and temperature, bullet resistant panels of fiberglass progressively delaminate as a bullet penetrates, distorting and flattening the projectile and dissipating the energy. More energy is consumed as the bullet penetrates the high-strength glass fibers.

Multiple customizable underground bunker floor plans to meet your security needs. 

For a Free Quote, call us at (816) 438-7171 or



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