There are a few key ways that galvanized pipe fittings are tested:

Visual Inspection

Fittings are examined for defects like cracks, holes, uneven coating, etc. This checks quality.

Coating Thickness Test

Using instruments like a micrometer, the zinc coating is measured to ensure it meets the required minimum thickness specification.

Adhesion Test

The coating is scratched then checked for signs it is firmly adhered to the steel substrate and won’t peel off easily over time.

Bend Test

Samples are bent to check if the coating cracks, flakes or has other defects from flexing. Ductility is important for installation.

Torque Test

Threads are assembled and fittings are tightened to gauge strength and observe if coating holds up to twisting/turning stress.

Impact Test

Parts may be struck to evaluate resistance to potential damage from being dropped or handled roughly during use/transport.

Corrosion Resistance Test

Samples are subjected to high humidity, salt fog or other corrosive conditions to verify coating effectively prevents rust.

Pressure Test

Assembled fittings are filled with water or air under hydraulic pressure to verify ability to hold seal long-term under working loads.

Proper testing helps ensure galvanized plumbing components will maintain integrity and corrosion protection over the lifespan demanded.