Air compressor hose size

[Ashton Crusher]

I've often wondered how much of the "energy" is getting lost thru pressure drop in the hose from my air compressor to the tool. Plus the thru hole in the fittings is pretty small. Yet none of the regular outlets seems to carry any larger diameter hose or fittings. I think the standard is around 1/4" or maybe 3/8. It' seems like a larger hose would make tools that use a fair amount of air work a lot better. Has anyone used larger hose and can offer a comparison?

[Ed Pawlowski]

There are variables. Any restriction can cause a performance loss but a

1/4" diameter passage can carry quite a bit of air. In the case of impact wrenches, nail guns, the amount fair per shot is minimal. Some spray guns, sander, bead blasters can take considerably more cfm. In the case of a nail gun, the pressure drop is negligible because of the recovery time between hits, even on a fairly rapid pace. The larger the house or piping in the system, the more reservoir you have , thus lessening the impact of the orifice size at the point of use.

[Jim]

See this link for a full explanation:

Hope that'll help... Jim

[Phisherman]

The material, length, amount of connectors, pressure, turbulence, temperature, humidity, leaks(!) can greatly affect the volume and "behavior" of delivered air. When using a blowgun short air spurts are often better than one long slower blast. With a larger hose of the same material the hose itself can store more energy--may be good (or not) depending on your specific application/tool.

[larry moe 'n curly]

Graph showing pressure loss per 100 feet (loss is proportional to lengty) for hoses from 1/4" to 1" diameter. Even going from 1/4" to

5/16" can help if the compressor is marginal:

[Ashton Crusher]

Excellent. Looks like the drop isn't nearly as bad as I thought it might be, perhaps 10 psi for my worst case.

[Stormin Mormon]

I have not done comparison. My best SWAG is that the couplings are the big loss item. So, if possible, thread the hoses together without the quick disconnect couplings.

From my fire department days, I know that water hoses benefit greatly from larger sizes. I do try to buy larger garden hoses for that reason.

[Bob F]

3/4" garden hoses make a big difference from 5/8" hoses. Especially if the pressure is marginal.

[Joe]

The answer is obvious. Always use 3/8" hose. Only one company makes high flow fittings for the standard 1/4"NPT outlets on the hose and that is MIlton. The ordinary box store fittings are M type, the Milton high flow are the V type. The V type rate of flow is nearly double the M type and I have been using them for a couple of years now for HVLP spray guns and general shop use. Auto body supply stores carry Milton stuff if you don't find it at your local Farm & Fleet.

Joe