Desander machines; desilter machines; high pressure pumps for washing appliances and installations; linear motion shale shaker machines; standard shaker machines; mud agitator machines; mud hopper machines; mud gun machines; mud bucket machines; parts and fittings for oil and gas well machines, namely, gate valves, shear relief valves, reset relief valves, float valves, plug valves, butterfly valves, hydrocyclones, choke nipples, hammer unions, fluid end modules, and liners, pistons and piston rods; solids separation shaker machines