Agilent Technologies AA Series User Manual page 19

Use acetylene at pressures lower than 105 kPa (15 psig). At pressures
above this level, acetylene can explode spontaneously. Your Agilent
AA is designed to operate at fuel supply pressures between 65 and
100 kPa (9.5-14.5 psig). Refer to the Specifications section or the rear
of the instrument for the exact range and recommended pressure.
Do not use any tubing or connector that reacts chemically with
acetylene. Never pass acetylene through copper tubing, or brass
tubing or fittings containing more than 65% copper, since this may
provoke an explosion. Never bring acetylene into direct contact with
copper, silver, liquid mercury, gaseous chlorine or grease, as an
explosion could result.
Use only acetylene that is packed in acetone. Some gas suppliers
offer acetylene packed in material other than acetone. While these
alternatives may overcome some of the disadvantages of acetone,
they may also introduce the more serious problem of corrosion in the
gas control module and must not be used with Agilent atomic
absorption spectrometers.
If the pressure in the acetylene cylinder is allowed to fall below
700 kPa (100 psig), or the consumption is greater than 1/7 of the
cylinder contents per hour, acetone may be carried over from the
cylinder and into the spectrometer. Acetone in the spectrometer can
damage seals, O-rings and hoses, degrade analytical performance and
precipitate flashbacks.
Minimize the amount of acetone which is carried over with the
acetylene by:


If high rates of consumption are observed then connect 2 or more
cylinders in parallel to a manifold. This reduces the rate at which
acetylene is drawn from each cylinder.
Agilent 240/280 Series AA User's Guide
Replacing cylinders when their contents pressure drops below
700 kPa (100 psi)
Ensuring that the rate of acetylene drawn off from each cylinder
is not excessive.
Safety Practices and Hazards
19