Burst pressure is sometimes defined as the point at which something such as a valve or hose will fail as a result of pressure, and it may also be defined as the point right before failure will occur. In either case, this pressure could be considered an expression of the maximum pressure which something can endure before it will break. It is important to consider burst pressure when designing any sort of system which is used with pressured materials such as water, gas, and various fluids, whether that system is the radiator in a car or a municipal water system.
A number of factors can influence this pressure. Knowing the parameters, an engineer can calculate burst pressure and work backward to determine which kinds of components could be used. Obviously, one major factor is the material being used to make a valve, pipe, or holding chamber. The quality of the material and its thickness can determine how much pressure it will withstand. Another factor is maintenance; a brand new valve is less likely to fail than an old valve, and a well maintained valve is less likely to break than one which has been neglected.
Factors in the environment can also be involved. High heat may lower burst pressure by weakening the material, and the composition of materials being carried in a pipe can also be important. A garden hose, for example, may be more likely to burst if the water is mildly corrosive, because it can eat away at the hose. Likewise, piping which is subjected to sun, scouring winds, and the elements will break down more quickly than safely sealed piping. Conditions such as extreme cold can also be a factor in burst pressure.
A burst pressure test can be conducted as part of materials testing to see what kind of conditions a component can withstand. During this type of test, the pressure is gradually increased to see when the component will burst. Taking this into account, the product developers can determine whether or not the device is appropriate for the intended use. It is important to make sure that components exceed the potential pressure of the system so that in the event of a pressure spike, the components will hold.
Having components such as hoses and valves fail can be very dangerous. A burst at high pressure may create tiny projectiles which could injure people who happen to be in the way. The unexpected release of pressurized materials can also pose a safety threat.