Prior to assembly, valve components must undergo the following processing steps:
Depending on processing requirements, certain components must undergo polishing treatment; their surfaces must be free of machining burrs and similar defects.
All components must undergo degreasing treatment.
Upon completion of degreasing, the components must undergo pickling and passivation using a phosphorus-free cleaning agent.
Following pickling and passivation, components must be thoroughly rinsed with purified water to ensure no chemical residues remain; this step is omitted for carbon steel components.
Each component must be individually wiped dry using a non-woven cloth, ensuring that no lint or fibers remain on the surface; alternatively, components may be dried using clean nitrogen gas.
Each component must be individually wiped using a non-woven cloth or precision filter paper dampened with analytical-grade alcohol, continuing until no discoloration or residue is visible.