Abstract: This paper concisely explains the key points in the commissioring of steam jet vacuum pumps on job sites, Such as: discharging of condensate in steam lines, reduction, of the pressure and the humidity by pressure regulating valves and the calculation method of hydraulics in water transporting pipes for condensers. This paper relates to a method of equivalence for inspection of leakage in vacuum system by applying the method for building-up of positive pressure instead of the method for building-up of vacuum.