New hydraulic piping requires what prior to use?

• A. Flushing and pickling
• B. Sandblasting
• C. Leak testing
• D. Paint coating

Answer: (A)

New hydraulic piping must be cleaned inside before it goes into service to prevent contamination that can damage components and reduce system reliability. Flushing removes loose debris, oils, and any manufacturing residues by circulating fluid through the line. Pickling chemically cleans the interior metal surface, removing rust scale and other contaminants and creating a more corrosion-resistant surface. Together, they ensure the piping is clean and ready for hydraulic fluid, helping protect pumps, valves, and filters from damage and fouling.

Sandblasting interior surfaces can leave abrasive material or cause roughness that may contaminate the system. Leak testing is typically performed after the piping is cleaned and assembled to verify there are no leaks, not as the initial preparation. Paint coating inside the pipes would introduce foreign materials into the hydraulic system and is not appropriate for interior surfaces.