Air pressure settings?

[ryanbrown999]

At work I want to get rid of the regulator on my gun. I was wondering if anyone knew of the pressure drop of a 50" hose?

Basically I have a Devilbiss DAD-500 unit with a diaphragm regulator on it and was wanting to know what pressure i could set my unit at to achieve the proper pressure at my gun. For instance if I set the air pressure at 45 psi at the unit I will get 25 psi at the gun.

Make sense or should I go into more detail?

[Hub]

What is the ID of thr 50' air hose and how old is it - Those factors will have a bearing on subject.

Air delivery test - works for all air spray guns
Turn the fan control knob all the way to the left (thats full open)
Same with the built in air valve if it has one
Set the wall regulator at 50 - 60 PSI
Attach a cheater valve with gage in the closed position to the gun
Attach air supply hose to the valve
Gun in hand and with the trigger in the full back position open the gaged cheater valve full open check the pressure if its not what you want increase or decrease the pressure USING the wall regulator- MAKE A NOTE OF THE READING SO YOU CAN REPEAT. Remove the gaged air valve from the gun AND ATTACH HOSE DIRECT TO GUN. Now you know the drop in PSI from wall to gun.
Cheers,
"HUB"

[jcclark]

And even better.
(air regulators can restrict cfm)
get some fittings and a gage and make one of these.
Easily attaches to any gun, regulate at the wall to desired psi
then disconnect and know you have the right psi.


Also: Switch your fittings to 3/8" instead of the std 1/4" and you'll
see a big difference.
Mine came from Home Depot and connect to std 1/4" hose ends.
($10.00 for a kit)
It's not the fitting od, it's the inside opening in the female
quick disconnect that's half the size. that's the bottleneck.
The 3/8" ones are a lot bigger.
They made a huge difference for me.

[Hub]

Jim, were you talking subject, needle & seat, or ball valve air adjusting valves.
Cheers,
"HUB"

[jcclark]

I'm not sure, All I know is a lot of air valves I've checked
the specs on are a lower CFM rateing than some HVLP guns.
I guess that's why some advertise they're made for HVLP guns,
even though most are on the low end of the scale.
I've seen some HVLP's pull as much as 15 CFM.
Few regulators will supply that much at the lower presure setting
for spraying. I'm convinced most painters aren't getting the CFM
they need. I painted for years with a starved set-up and didn't even
know it. When I switched to bigger fittings, and adjusted got
the cfm right, my gun sprayed better like never before.
It was an amazing difference, and I never knew it before.