The failure problems of elbows and pipes facing a lot of industrial foundations like Cement Plants. This work investigated reasons and factors that cause the failure due to mechanical wear (Erosion) for the inside surface of elbows and pipes used in cement transportation (pneumatic conveyor) which manufactures from low carbon steel and finds out a method for reducing this failure. The technique of thermal spraying is using to coat the surface of samples with layers of nanoparticles of tungsten carbides (WC) of different thicknesses (30, 40, and 50μm). The test was done for these samples by placing them inside the elbow under the same operating conditions, moreover the standard test (pin on disc). The results showed a decrease in erosion rate by 71% for the sample coated with 50μm of WC layer, while the results of the pin on disc test showed a decrease in erosion rate by 97% for the thickness of 50μm. The SEM Images showed a coating thickness layer of more than 50μm will be subjected to flacking and failure. The numerical simulation was also implemented to simulate the erosion profile inside the elbow, and the agreement with experimental results was 90%.