The practice of not leaving the regulator gas flow adjusting
screw/knob turned in when the torch isn’t in use is to get the
pressure off of the diaphragm and spring, in the regulator that
controls the gas flow. as some of the gauges show the tank pressure
and not the pressure being used at the torch tip.
The marks either numbers or letters or some other means of adjust
the gas flow for the tip size. (consumption) in cu ft per hour. The
only chart I have handy is for the Turbotorch brand prest-o-lite
air/acetylene torch handles. For S-1 or S1QD tips either the
standard or quick disconnect handles is .53 to .89 Cu Ft per hour. to
the S-6/S6QD 8.8-14.8 Cu-Ft per hour.
The pressure of the coming out of the torch is between 5 psi to 14
psi. As at 15psi acetylene gas becomes highly unstable in free air.
That is why it is dissolved in the acetone liquid inside a porous
filler material in the tank. In the old days it was asbestos and or a
cement mix. now a days it is a assortment of spaceage materials.
The chances are you have an old school tank, There are some that
have been around and really have been used on a bus,truck as a light
With a full new tank having the regulator set and opening the tank
valve is when you have the best chance of having a regulator
failure. As most people open the tank valve more the 1/4 open first
thing and then wind the valve back to the 1/4 open position.
The purpose of which is to make it faster to close if their is a
“Those B tanks used for welding are really abused by the welders. I
remember worrying about the same thing! Jean Menden”
Welders generally don’t use a B tank, as there are 20 cu ft
acetylene and oxygen back pack tanks that don’t require as refilling
as often. if they need to take a small rig up a ladder etc. Welding
and cutting use more gas per hour.
The B tanks and the smaller MC tanks are used by plumbers for
soldering the most, followed by Heating,AC/refrige repair and
install. The largest user group for these tanks are the hobbyist of
And the biggest problem is the people that will not use the correct
valve wrench on the square stem valve. I think that they are around
a buck at the LWS. But use vicegrips,crescent wrenches or almost
close open end wrenches. There is a reason that the proper wrench is
a square closed end.
The second group is the sacred people because of the stories that
they have heard and so they crank the valve tight. Which causes
problems when they go to open it the next time, which will lead to
leaking seats in the valves.
The last bit of advice is don’t let the tank hang around your work
area unsecured make sure that it can’t fall over. If the valve snaps
off, the tank will tank off like a rocket with catastrophic results.
Hope this helps.