I'm very new to painting, I have a iwata lph400 and im using nason select clear 498-00. most stuff I have read says pressure at gun 16 psi (ish) the pdf for the clear says

SPRAY PRESSURE
Conventional
Gravity Feed: 30-40 PSI at the gun
HVLP: 8-10 PSI at the cap

so what should it be at the gun for hvlp???

I have sprayed ok but I have to move really slow accross the panel to try to prevent orange peal and I see other people(youtube) spraying clear with lph400 and moving MUCH faster then me and theirs seems to lay down better also. please give this noob some good advice lol

Kick your air pressure up to about 20/22 labs, 75% overlap and about 4 or 5 inches from the panel. You can hammer that clear on and it behaves pretty well.

Chuck

It should be exactly what the gun says for it to be.
Look at your cap, it tells you the PSI at the gun.
that's measured at the inlet of the gun with the trigger fully pulled.
That setting will give you 10 PSI at the cap like the specs call for.
The gun itself regulates down.
All guns are different, some HVLP's take upwards of 45PSI at the gun but
that will still give 10 PSI at the cap.
So it's important to know what your gun calls for.
Most painters spray at about 5 to 8 PSI more than what's called for,
and that's fine, but the gun spec is a good starting point.

I'm also new at this, but from my research (I have this gun also), this is a lower pressure gun and therefore requires a slower hand speed than those that require the psi you mention. If the youtubers sprayed slow with their gun (higher psi), they would probably have lots of runs. The pros will correct me if I am wrong. From what I recall without the book, that gun requires 14-18 psi, which is far below what you mentioned.

Good luck...Al

Just an FYI. I was on another forum and the gentleman stated that he used 20-25 psi for base coat (Pro spray) and 30 psi for clear (**********). He made it clear that the psi was giving him the best spray pattern, so test and adjust.