I'll offer some more description about the screw-on disposable tank-type
MAPP torch I've been using. The MAPP gas is meant to mix and burn within the
burner tube on all of them of this type that I've seen.
I know this seems weird, but the opening in the bigger mixer/burner "tip"
that I have is about 3/8" diameter. The last 2" of tube is where the
combustion begins.

I don't have any experience with a refillable cylinder, regulator and hose
type MAPP/air torch. I dunno if the construction has any similarities to the
screw-on type torch.

The orifice/jet is located at the base of the tube at a venturi (with
considerably larger air holes than a propane torch) where the gas flow draws
in air, then there is a twisted helix of sheet metal within the tube, which
I think is intended to swirl the mix to ensure that the air and the MAPP gas
are mixed.

Combustion begins to take place within the burner tube (in the last 2" of
length), which is why the end of the tube glows. Most of the flame that
exits the tube is blue, and extends quite a ways past the tube end,
especially when the regulator valve adjustment is close to wide open.

The smaller mixer/burner "tip" looks more like a conventional cutting torch
tip, only at the end, except the fluted center is set back inside about 1/8"
from the end of the stainless steel tube.
For this smaller tube, the combustion takes place outside/just beyond the
end of the fluted insert, so there is no red glow from the smaller tube/tip.

It should be mentioned here again, that connecting a MAPP gas tank to a
regular propane torch won't result in the same heat output as when MAPP gas
is used with a MAPP torch.
I haven't measured the temperature or heat output, but the performance is
about the same as just using propane, when using a propane torch.
As mentioned above, the air intake holes/ports at the venturi are much
larger on a MAPP torch, suggesting that the gas/air balance is a lot
different.

--
WB
..........
metalworking projects
www.kwagmire.com/metal_proj.html


"Wes" wrote in message
...
I don't think so. Look at oxy/act equipment, far higher temperatures and
the tips are
made of what looks to be copper to me.

The burning happens outside the tip with MAPP.

Wes