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Hi Flow fitting?

2K views 9 replies 5 participants last post by  Javelin69 
#1 ·
Hi gang,

Had a quick couple of questions. Now I've heard that it's best to use hi flow fittings for your spray guns and sometime your pneumatic tools as well, i.e. da's and so on. But I also heard that using a 3/8" hi flow is the best. But what do you do when your air hose has a 1/4" mnpt ends and most spray guns 1/4" npt inlet? Am I stuck with just using a 1/4" cause I really don't feel like have a foot worth of reducers on my rig just to get that more cfm's? Also, I upgraded my compressor to a Craftsman Pro 5hp, 2 stage 80 gal. I think that should more than make up for the smaller 1/4" fittings, don't you think? :confused:
 
#2 ·
Flow is dependent on pressure vrs restriction relationship. You can increase flow by either reducing the restriction or increasing the pressure. Not sure with paint guns specifically however I'd suspect it's best to reduce the restriction rather than increase the pressure on the trigger mechanism of the gun. There are higher flow 1/4 fittings on the market that will help but putting on 3/8 fittings on a 1/4 hose.....the hose is still the restriction.
 
#3 ·
1/4 In. x 3/8 In. Automotive Series Coupler and Plug Kit 4 Pc are cheep high flow quick connects.. the plugs are threaded 1/4 NPT the coupler is threaded 3/8NPTF. to go on the end of 1/2" id hose. but with a bushing reducer works great on 3/8 hose..

there are also amflo versions.. Amflo | plews-edelmann that you can get in many hardware and tool stores.. some better paint stores.

to eliminate restrictions.. select any short whip hoses carefully.. i had a friend who complained.. he had a 1/4" id whip hose on every tool..

if you have needs that require air tool or spray gun use at the end of the hose.. you can modify air tanks with boiler drain valves..

the image is my friends old air tank.. his valve leaked.. now it will hold air for months.

in one shop i worked at.. we needed the 3/4 impact out in the parking lot..

i built a modification of what you see... but it had a backwards installed quick connect.. so the plug stayed on the tank to connect to the shop air hose on the side fitting.. the straight thru fitting had a 6 foot 1/2" id hose to connect to the 3/4" impact. this converted the spare air tank to a surge tank...

the body guy found it handy too.. he used it to do some stuff out in his area.. using his air chisel.


another friend had a extra 80 gallon tank from a former compressor that the pump died after a short life.. he actually hooked both the new 80 gallon and the old 80 gallon together.. so he had 160 gallons of air in reserve..
 

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#5 ·
Ok, so when you mean a whip hose, that would be a smaller i.d. hose that goes from the main line to the spray gun? Because the only hose that can use 3/8" ends would be a 1/2" and that's a bit excessive I think in size. I use that at work and its a ***** to move around, so I can't really see painters using them.

But how long and what size whip hose to use?
 
#6 ·
What would make you think that? There are all kinds of 3/8" hoses out there with 1/4" NPT ends. And all kinds of hi-flo ends for 1/4" NPT. That's all I use anymore. Don't confuse pipe thread diameter with hose or tubing diameter...

Russ
 
#8 ·
Yup, now you have to think about your whips. I use a cheapo HF 1/4" coil-hose for my bench blow-gun. Just for giggles, I put my HVLP gun on this whip and couldn't even get 5# on my (gun mounted) regulator with 80 PSI on the hose and the trigger at full pull...

Russ
 
#9 ·
the 3/8" fittings still have 1/4" thread. It's not the thread size that's the restriction, it's inside the fitting. On a standard size fitting, it's very restricted if you look inside. On the big 3/8" fitting it's nearly the same diameter as the hose. It made a world of difference in the available air to my gun.
 
#10 ·
Ok, I was able to figure out what you guys meant. But here's the crazy thing. We use those exact same fitting at work. I realized that all my air tools at work use a 1/4 npt fitting and the fittings at work are to big for my home stuff. I just went over to McMaster-Carr and picked up a bunch of fittings and couplers. Thanks for all the help gang! Now to wait for the new compressor, being delivered on black Friday. Oh yeah!
 
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