A:Answer As long as the pressure cooker has a rating of 120v/240v with Hertz allowance of 50hz/60hz then an adapter will work. If your appliance is only rated 120v at 60hz then you would need a converter, not just an adapter. In America, the sine wavelength of electricity is 60hz so all electronic devices are made for this wavelength, if used in a European country that produces a 50hz sine wavelength, you would destroy the inner working of your device.