I have a Cook's Essential 8 quart by Salton. It has dual pressures, LOW is 10 PSI and HIGH is 15 PSI. This is not (to the best of my knowledge) effected by the ambient air pressure, like the old fashioned pressure cookers were. The manual does not mention any changes to the cooking time due to altitude. 15 PSI should cook at about 270F. I don't know the temperature for 10 PSI, but I think it is around 240F.
