How Heat Exchanger Tube Is Inspected Before It Ships

Non destructive checks on every tube

Eddy current testing looks for surface and near-surface discontinuities along the full tube length.

Hydrostatic testing proves the tube against internal pressure and finds through-wall defects that eddy current may not resolve.

Mechanical testing

Tensile testing on the universal testing machine establishes yield, tensile strength and elongation against the specification.

Flattening and flaring tests check ductility and the tube's behaviour when it is rolled into a tubesheet.

Impact testing and hardness testing are added where the specification or the service calls for them.

Chemical and metallurgical checks

Chemical composition is confirmed with a spectrometer and a direct-reading optical emission spectrometer.

A metallurgical microscope is used for structure examination, and intergranular corrosion equipment is used where the grade and specification require that test.

Dimensional inspection

Outside diameter, wall thickness, length and straightness are measured and recorded.

On finned tube, fin pitch, fin height and finned length are verified as well - these are the dimensions the bundle designer assumed.

What this means for a buyer

Raw material comes from established suppliers including Yongxing steel.

Testing is done in house on our own equipment, which is why certificates travel with the shipment rather than following weeks later.