40 Custom manufacturing for others of replacement parts for machinery in the oil and gas industry, namely, custom manufacturing for others of discharge modules, suction modules, liners, valve bodies, valve seats, pistons, piston rubbers, piston rods, extension rods, cylinder heads, valve covers, crankshafts, bearings, crossheads, guides, gears, butterfly valves, forged gate valves, float valves, relief valves, pressure gauges, hydraulic seat pullers, oilfield chains, gaskets, baffles, dampeners, discharge manifolds, suction manifolds, diaphragms, discharge crosses, and handling tools for use in the oil and gas industry