so 4000 psi = 2.757903e+007 pa = 2.757903e+007 / 106 mpa
1 psi = 6.89476 kPa (rounded) 1 kPa = 0.14504 psi (rounded) 1 mPa = 1,000 kPa
Formula: MPa x 145 = psi
4,000 pounds per square inch (psi) is the everyday term, it is read everyday on gauges everywhere. (Tire pressure is in psi.)
there is no such thing. psi is how much oxygen is in a certain amount of space (mostly used for deep divers