PerkinElmer aanalyst 200, User Manual

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AAnalyst 200 User’s Guide
3-19
Flash arrestor
PerkinElmer recommends the use of the Flash Arrestor (P/N N930-0068). The flash arrestor
provides a positive gas shutoff by checking the reverse flow under all conditions. It also stops the
gas supply when a flashback occurs. The flash arrestor can be directly connected to the acetylene
fuel line.
Piping/tubing/fittings
Use galvanized iron, steel, or wrought iron tubing. Never use copper tubing with acetylene. Joints
may be welded or made up of threaded or flanged fittings, typically stainless steel or aluminum,
or brass composed of less than 65% copper. Rolled, forged, or cast steel or malleable iron fittings
may also be used. Cast iron fittings cannot be used safely for acetylene lines.
Safe use of acetylene
•
Periodically check for the presence of acetylene in the laboratory atmosphere, especially
near the ceiling.
•
Never allow the outlet gauge pressure to exceed 103 kPa (1.03 bar, 15 psig); acetylene can
explode spontaneously above this pressure.
•
Prevent acetylene from coming into contact with copper, silver, mercury or gaseous
chlorine.
•
Solvent carryover.
If the acetylene cylinder pressure falls to below 600 kPa / 6.0 bar / 87 psig (at 20 °C), some of the
solvent used to stabilize the acetylene (such as acetone) may be carried over into the burner. This
could influence the characteristics of the burner with a resulting influence on the analytical
results. Change to a new acetylene cylinder when the cylinder pressure falls below this value.