3492 Fluid Power Valves and Hose Fittings Establishments primarily engaged in manufacturing hydraulic and pneumatic valves, hose and tube fittings, and hose assemblies for fluid power systems. Establishments primarily engaged in manufacturing fluid power cylinders are classified in industry 3593; those manufacturing fluid power pumps are classified in industry 3594; and those manufacturing hydraulic intake and exhaust motor vehicle valves are classified in industry 3592.