Hi,

One of my customers is building units, to be exported to US.
We deliver components who have a UL certificate. For the condensor (air cooled) he uses a coil comming from an other supplier with copper tubes with a thickness of 0,28 mm; the MWP is (according to the coil supplier) 33 bar.
Now the UL inspector says that to get an UL certificate, a minimum wall thickness of 0,65 bar is required.
Does anyone know if this is correct? Is there a minimal wall thickness requirement in UL? (Or is it a pressure test requirement ...)

Best regards