Best high flow air compressor couplers?

S

Sid Post

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Oct 14, 1998
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I am looking at Flexilla and Milton Type V couplers and plugs and was curious what everyone's thoughts were on these or others? Is one better than the other? Am I overlooking something better at a similar cost?

My friend and I have dual stage 5HP 60~80 gallon tanks that put out ~15CFM at 90PSI. Airing up 80PSI tires is extremely slow with our current setup. I have read good things about "high flow" couplers and plugs but, the marketing materials leaves me wanting real-world knowledge and experience and not more marketing 'hype'.

TIA,
Sid
 
From my experience, high flow fittings are used when you require volume. Not pressure. For instance, when painting with HVLP or Approved Transfer Efficiency spray guns or filling large items like air mattresses that have a larger inlet.

If the tires you're filling have a standard diameter inlet, the volume restriction would happen there anyway. If the inlet is 3/8" or larger, high flow fittings would get you there faster if the compressor can keep up.
 
The main issue is low volume air flow at the end of the air line combined with the high PSI needed. A 30PSI tire fills fine in a reasonable amount of time, a larger tire at 80 PSI doesn't due to the volume (CFM) which seems to decrease as the PSI goes up. I was hoping a larger diameter 'bore' in the plugs and couplers would allow more CFM at higher pressure levels.

The compressor claims ~15CFM (of 'new' air) at 90PSI but, fill time would suggest either it isn't really doing 15CFM or the tire in question is too large for normal road use. The tank should deliver way more than 15CFM for a while at least since it is well above that PSI when fully charged. Is a 60 or 80 gallon air compressor tank at ~120PSI really too small to fill a truck or trailer tire at 80PSI in a reasonable time frame?
 
What is your expectation vs what are you actually seeing?
What size tires are you inflating and exactly how long does it take you?
Are they single or dual wheels, is there any apparatus tying duals together such as an air equalizer?
 
3fifty7 said:
What is your expectation vs what are you actually seeing?
What size tires are you inflating and exactly how long does it take you?
Are they single or dual wheels, is there any apparatus tying duals together such as an air equalizer?
Click to expand...

A single 275/70-16 taken from 40PSI to 80PSI takes ~5 minutes. That's ~20 minutes plus time to move from tire to tire for example which is why I think I have a 'flow restrictor' somewhere besides the tire valve itself with only 50' of air hose. I have been at truck stops and garages where the same fill takes ~90~120 seconds with a 1/2" hard line connected to an air line that appears to be much abused and smaller but only a 8'~12' in length. Tractor tires are a whole different story and are a set it and walk away proposition (30~60 minutes to bump up a few PSI).

If a ~$20 set of couplers and plus a ~$40 'big' hose will get me underway faster, I think it would be worth it to me. Perhaps I'm expecting too much from a 60-gallon dual stage 5HP air compressor?
 
Wow, those are unacceptable times. Do you have a dryer between the tank and supply line that could be restricted? Or is the line plumbed directly into the tank with a valve? Are you positive the valve is completely opened?
 
3fifty7 said:
Wow, those are unacceptable times. Do you have a dryer between the tank and supply line that could be restricted? Or is the line plumbed directly into the tank with a valve? Are you positive the valve is completely opened?
Click to expand...

That's why I'm looking to replumb everything. I'm wondering if my line has a problem in it. I figure if I'm replacing the air line and hose, I might as well go for some newer higher flow connections too. I could almost do as well with a ~$100 pancake air compressor. :( What a waste of a nice big dual stage air compressor.

I'm tempted to just get another 100' of air hose and plumb direct into the big tank.
 
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