that should be before the filter stack relief lifts. I agree with others that there is different regional difference is standards being cited by some posters.. I dont think you will have a problem in the US regarding many of the issues brought up. I also dont think you will have a problem with 4500 if you are filling a paint gun fiber tank. the psi is not high for very long as opposed to filling a bank tank. that compressor's duty cycle is not designed to fill cascade banks 3000 or 4500. I am assuming that you are already filling your fiber tanks with this compressor.I bought it, btw the pressure relief valve on top of the filter tower has a tag attached that says Set 4500psi so i guess id only be able to fill to 4400psi or so.