Future carbon-free industrial processes require electrified steam generation methods, e.g., high-temperature heat pumps (HTHP). Alternatively, mechanical vapor recompression (MVR) may be used to recover waste heat or waste steam. This research combines HTHP and MVR by implementing an MVR rotary lobe blower as the first stage compressor in a two-stage 400 kW R-718 HTHP with a total temperature lift of 50 Kand an evaporation temperature of 80 C. Before assembling the R-718 HTHP, the liquid-injected rotary lobe blower was tested in an R-718 compressor performance test stand. This paper focuses on the design of the test stand and the performance test results for different shaft speeds, pressure ratios, and suction pressures. The test results are compared to the initial manufacturer's coefficient-based correlation, which is then modified to fit the experimental data. The updated model predicts the compressor's behavior in the R-718 HTHP regarding cooling capacity, efficiency, and COP.