The recently predicted mechanism of orbital pumping can enable the

generation of pure orbital current from a precessing ferromagnet (FM) without the need

for electrical current injection. This orbital current can be efficiently injected into an

adjacent nonmagnetic material (NM) without being hampered by electrical conductivity

mismatch. However, experimentally identifying this novel effect presents significant

challenges due to the substantial background contributions from spin pumping and spin

rectification effects (SREs). In this work, we disentangle the effects of orbital pumping

from spin pumping in bilayer structures composed of Nb/Ni and Nb/Fe60Co20B20 by

observing a sign reversal of the measured voltage. This reversal arises from the

competing signs of the spin and orbital Hall effects in the Nb. We establish methods to

differentiate the pumping signal from SREs by analyzing the distinct angular dependence

of the measured voltage and its spatial dependence relative to the radio frequency

excitation source.