The triple point of any substance is that temperature and pressure at which the material can coexist in all three phases (solid, liquid and gas) in equilibrium.Triple point of water is a single point in P-T phase diagram of water where the three phases of water coexist.

The triple point of water is defined to take place at 273.16 K, where K is the SI unit Kelvin. Unlike Celsius and Fahrenheit scales, Kelvin is not measured using degrees; we merely say "Kelvin."

It is important to note that the pressure the triple point exists at is 4.58 torr in SI units or .006 atm.

The triple point of water is defined to take place at 273.16 K, where K is the SI unit Kelvin. Unlike Celsius and Fahrenheit scales, Kelvin is not measured using degrees; we merely say "Kelvin."

It is important to note that the pressure the triple point exists at is 4.58 torr in SI units or .006 atm.