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Air compressor fittings, couplers, lines, valves

Posted: Mon Mar 30, 2015 12:53 am
by BOOT
Ok so I'm finally getting round to upgrading my air lines on my almost 20yr old compressor and froze plain reg. Now I'd like to run a 3/4 impact for those stubborn hard to fit a giant pipe situations :) and form what I can tell it's more about volume than psi. So of course the more I read, research & inspect the deeper the hole/cost gets to having a true hi-flow setup. I'd like to do a shut off valve with a short line to a wall mounted reg/filter with a T off for two lines. One side for all tools & the other for a 3/4 impact(I'll make an adapter to use same as other side when not using impact).

1st I read about the hi-flow V style couplers/fittings and as far as I can tell V style, H style & 3/8" M style(not 1/4" M that every store carries) are the same ID. H & 3/8" M look identical to me and prob are the same thing with diff brand labels. Since those three sizes are the same looks like the next up is a 1/2" M style too match a 1/2" line. So I'm thinking 1/4" V style one end and 1/2" M style the other on the T.

Next I noticed all the lines I saw at the stores have a step down inside the threaded ends and then open back up. Looks like a npt to hose barb of equal size is more ideal. Even found some 1/2" M too 1/2" hose barb.

So then I looked at shut off valves to control leak down. Because if I just shut off the compressor it still has to recharge after sitting idle for awhile with total leak down. Even the 3/8npt "full flow" valves are a step down so for the 3/8npt pipe ID out of my compressor so I'll have to use a 1/2npt valve with an adapter.

Sure feels like I'm doing a car fuel system. My 6.5hp 120psi compressor never has been that strong, but now I'm thinking it's all these dang choke points. The older I get the more it seems everything as it comes, is wrong.

idk maybe I'm over complicating it.

Re: Air compressor fittings, couplers, lines, valves

Posted: Fri Apr 03, 2015 3:26 pm
by gofaster
Instead of making the whole system big, just get a portable tank. On one end install a shut off valve and a whip to connect to any of your standard air drops around the shop. On the other end install the largest hose barb you can, with a short length of BIG hose. When it's time to drag out the big impact, charge your portable tank and go. This will give you the big hit you need to break something loose, then go back to normal size tools to finish the job. That's how I did it back in the days before I had a big air compressor and a heavy duty air system in the shop.

Re: Air compressor fittings, couplers, lines, valves

Posted: Fri Apr 03, 2015 9:39 pm
by Kevin Johnson
gofaster wrote:Instead of making the whole system big, just get a portable tank. On one end install a shut off valve and a whip to connect to any of your standard air drops around the shop. On the other end install the largest hose barb you can, with a short length of BIG hose. When it's time to drag out the big impact, charge your portable tank and go. This will give you the big hit you need to break something loose, then go back to normal size tools to finish the job. That's how I did it back in the days before I had a big air compressor and a heavy duty air system in the shop.
That is a fantastic tip. Should be a sticky. =D>

Re: Air compressor fittings, couplers, lines, valves

Posted: Sat Apr 04, 2015 2:40 am
by BOOT
No shop line system for me just an old 60gal compressor. Still good tip, but already bought all my stuff to upgrade. FYI for anyone who buys 1/2" line with 1/2npt ends, it's only a tad smaller ID at the inside step of the ends than the ID of the 1/2" M style fittings.

Re: Air compressor fittings, couplers, lines, valves

Posted: Mon Apr 06, 2015 4:32 pm
by BOOT
Took a pic to show a friend on FB so figured I'd share it here as well.

Left to right 1/4 M style, V style(3/8 M style), 1/2 M style

Image

Re: Air compressor fittings, couplers, lines, valves

Posted: Tue Apr 07, 2015 1:59 am
by noice
Sometimes it is the fittings that can restrict flow, many of the quick connects actually suck when it comes to this. The male end might be unrestricted, but the female end has a spring loaded plate that the air must flow around to continue downstream.

Since most every air fitting is made this way, I like using lincoln style air fittings that you can plug in with one hand.

However the most crazy fitting I've ever seen is a true full flow fitting that can be plugged in with one hand, I don't even know the cost. They are called ErgoQIC full flow fittings by Atlas Copco. They also make crazy expensive air tools that have turbines in them instead of typical air motors.

Re: Air compressor fittings, couplers, lines, valves

Posted: Tue Apr 07, 2015 4:40 pm
by BOOT
hmmmm never considered the couplers might be a choke point, suppose it would be possible to connect the line to a T or distribution block and then even just put the line straight into the impact since I'd only use the larger line with that gun. I'd at least put a shut off valve on the tank end.

Re: Air compressor fittings, couplers, lines, valves

Posted: Tue Apr 07, 2015 8:34 pm
by Dave Koehler
I have a larger compressor. The shop line system is standard 1/2' drops and 3/4 or 1 inch main line (1 forget which)feeding the drops.
At the compressor I added an extra outlet for one of those big fittings and just plug in a big hose when needed.

Re: Air compressor fittings, couplers, lines, valves

Posted: Wed Apr 08, 2015 4:51 am
by BCjohnny
A few thoughts. I've installed several pneumatic systems over the years, and these are some of the conclusions I've arrived at........

Even the smallest shop can benefit from rigid lines (pipe) and the cost/time taken to install it is well worth it. As Dave says use 3/4-1" trunking and 1/2" drops. Ordinary 1/4" QR fittings work for most tools, but put at least three or four above the termination of each drop, branch off horizontally with all after the water trap but just one or two past the oiler (it's up to you where you put the reg). Extend the pipe vertically down another foot or two down and fit a ball valve for draining.

As regards the specific question, install a higher capacity 3/8" QR fitting in several locations, just below the trap/oiler/reg horizontal tap, straight off the 1/2" drop (tee fittings best). Size the flexible's bore accordingingly.

[Over here 1/4" 'PCL' type QR fittings reign, but I also use 3/8 'Schrader' QRs where needed. I also make up reducers, Schrader>PCL, for use at the rigid or at the flexible end as you always run out of QRs.........]

Re: Air compressor fittings, couplers, lines, valves

Posted: Tue Mar 01, 2016 10:44 am
by Monza Harry
I know this is an older post but I have some thing to share that may help out the OP and others with these questions of coupler flow. There is a coupler that is basically a 1/4 turn ball valve and a quick coupler in one. I have seen these at a local store that is now gone :( . But I found an online pic'/link not a good one but a starting place. These have a open line of sight hole straight through, should be very low restriction for those High Flow needs. Sorry I don't remember the pricing on them this was a while ago. Harry http://www.pneumaticsonline.com/oetiker2.htm

Re: Air compressor fittings, couplers, lines, valves

Posted: Thu Jun 23, 2016 4:05 pm
by tonyg64
Those German coupler/connections are great, I bought some from A Snap On dealer :)

Tony