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leave the wrench in place on the acetylene cylinder valve while the valve is open.
However, when two
or more cylinders have been manifolded together, it is sufficient to leave a wrench
on one of the cylinders. The point
is this: you should not be forced to waste time looking around for a suitable
wrench should an emergency make
it necessary to close the cylinder valve or valves without delay.
cylinder-pressure gauge on each regulator shows you the pressure in each cylinder.
In the case of both oxygen and acetylene, pressure
is a rough measure of contents.
If you are using a large cylinder of oxygen which when full contained 244 cf at
2200 psi and 700F (6.5
m3 at 15200 kPa and 200C),
the cylinder is half-full when the cylinder-pressure gauge reads 1100 psi (517
kPa), so that you have 122 cf
(3.2 m3) available. When the pressure in an
acetylene cylinder is approximately 125 psi at 700F
(862 kPa at 200 C) it is also true that the
cylinder is about one-half full. However,
if you are using a liquefied fuel gas, such as propane, cylinder pressure remains
constant until virtually
all the liquid has been vaporized. For that reason, regulators designed for propane
service are seldom supplied with cylinder- pressure
gauges. Liquid oxygen cylinders are equipped with liquid-level gauges which will
indicate the amount of liquid oxygen remaining in the
Gas Supplies to the Torch Always
use hose and hose connections made specifically for gas welding and cutting purposes.
has a green cover; acetylene hose has a red cover. Never interchange oxygen and
acetylene hose. Do not use
acetylene hose with propane unless you know that is acceptable for use with propane.
(Hose with natural rubber
liner is satisfactory for acetylene service, but not for propane service.)
Make up all connections dry; do not
use pipe-fitting compounds, thread lubricants, oil, or grease.
are designed with metal-to-metal seals. They do not require lubricants or sealants.
However, they must
always be made up wrench-tight, not merely hand-tight. Never
force connections which do not fit. If
you cannot run the threads together by hand with ease, either the
threads are damaged, or you are trying
to put together parts that were not made to go together.
If the hose does not have connections
on both ends, put these on next. Connection
nuts for oxygen hose have
right-hand threads, connection nuts for acetylene have left-hand threads. Instructions
for installing hose connections
are given in the Appendix