<P> Water mist systems are used for special applications in which it is decided that creating a heat absorbent vapor is the primary objective . This type of system is typically used where water damage may be a concern, or where water supplies are limited . NFPA 750 defines water mist as a water spray with a droplet size of "less than 1000 microns at the minimum operation pressure of the discharge nozzle ." The droplet size can be controlled by the adjusting discharge pressure through a nozzle of a fixed orifice size . By creating a mist, an equal volume of water will create a larger total surface area exposed to the fire . The larger total surface area better facilitates the transfer of heat, thus allowing more water droplets to turn to steam more quickly . A water mist, which absorbs more heat than water per unit time, due to exposed surface area, will more effectively cool the room, thus reducing the temperature of the flame . </P> <P> Operation - Water mist systems can operate with the same functionality as deluge, wet pipe, dry pipe, or pre-action systems . The difference is that a water mist system uses a compressed gas as an atomizing medium, which is pumped through the sprinkler pipe . Instead of compressed gas, some systems use a high - pressure pump to pressurize the water so it atomizes as it exits the sprinkler nozzle . Systems can be applied using local application method or total flooding method, similar to Clean Agent Fire Protection Systems . </P> <Table> <Tr> <Th_colspan="2"> Temperature </Th> <Th> Color of liquid alcohol <P> inside bulb </P> </Th> </Tr> <Tr> <Th> ° C </Th> <Th> ° F </Th> </Tr> <Tr> <Td> 57 </Td> <Td> 135 </Td> <Td> Orange </Td> </Tr> <Tr> <Td> 68 </Td> <Td> 155 </Td> <Td> Red </Td> </Tr> <Tr> <Td> 79 </Td> <Td> 174 </Td> <Td> Yellow </Td> </Tr> <Tr> <Td> 93 </Td> <Td> 200 </Td> <Td> Green </Td> </Tr> <Tr> <Td> 141 </Td> <Td> 286 </Td> <Td> Blue </Td> </Tr> <Tr> <Td> 182 </Td> <Td> 360 </Td> <Td> Purple </Td> </Tr> <Tr> <Td> 227 260 </Td> <Td> 440 500 </Td> <Td> Black </Td> </Tr> </Table> <Tr> <Th_colspan="2"> Temperature </Th> <Th> Color of liquid alcohol <P> inside bulb </P> </Th> </Tr>

What is the liquid inside a fire sprinkler