Relief valves are installed in each tube to prevent overpressure. The overpressure estimated to damage lungs is about 70 kPa. Injury from blast overpressure is a pressure and time dependent function. A third danger comes from air overpressure that occurs during the implosion. Primary injuries are caused by blast overpressure waves, or shock waves. This prevents the tubes bursting from overpressure. The overpressure from the explosion destroys most mines. Cab tightness allows the use of overpressure filtering. These spaces are also not designed to withstand overpressure. Its main purpose is to protect from shock waves and overpressure and also from earthquake. Concorde had an overpressure of (133 dBA SPL). There are two types of seep that can occur, depending on the degree of overpressure. The pistol was to then be used to fire an overpressure test cartridge generating . To preserve its outer form, a slight overpressure of about is maintained within the hull. Accordingly, most overpressure rounds are hollow points or other types of expanding ammunition.