Hi folks, I have a question regarding centrifugal compressors when a relief valve is included in the system. Allow me to explain... There is a centrifugal compressor supplying air to an aircraft engine. As altitude varies, the compressor provides enough pressure up to altitude "X" for the engine to operate at full manifold pressure. Now, in order for the pressure not to rise above the engine limits, a relief valve opening at max supported pressure. My questions are: 1.- At lower altitudes, when the relief valve is letting air escape due to the higher inlet pressure, is the power required to operate the compressor lower (because of the lower compression) or the same (because the air flow escaping through the relief valve) ? 2.- Similarly, is the compressor discharge temperature (which depends on compression ratio) lower or the same? Basically my doubt is if, internally in the compressor, the compression ratio and air flow remains the same making the required power and discharge temperature also remain the same as if the relief valve was not there. Hope that explains my question. Thanks in advance!