PerkinElmer PINAACLE 900 Series, Customer Hardware And Service Manual

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59
Flame Gas Requirements
The PerkinElmer Acetylene Regulator Assembly includes an adapter so that the
pressure regulator can be connected to cylinders requiring either CGA 300 or CGA
510 fittings as well as a connector for attaching the fuel hose assembly supplied
with the instrument. The fuel hose assembly is constructed of red neoprene,
reinforced with high tensile-strength rayon cord, and provides a rated working
pressure of about 1700 kPa (250 psig). The connectors are permanently mounted
at each end of the hose assembly for connection to the pressure regulator and
instrument gas controls, and use left-hand threads as per accepted practice for fuel
gas connections. (See Section 5 for more details.)
It may be desirable to have an acetylene filter between the acetylene tank and the
instrument gas control system to remove particulates and acetone droplets from
acetylene, protecting the gas controls and AA burner system from contamination
and corrosion. An Acetylene Filter (Part No. N9301398) and an Air/Acetylene
Filter Accessory (Part No. N9301398) are available from PerkinElmer. Some
countries also require the use of a flashback arrestor, such as PerkinElmer Part No.
N9307506 in the acetylene fuel line.
Acetylene is normally supplied dissolved in acetone, and a small amount of
acetone carryover with the acetylene is normal. However, as tank pressure falls, the
relative amount of acetone entering the gas stream increases and can give erratic
results, particularly for elements such as calcium, tin, chromium, molybdenum and
others whose sensitivity is highly dependent on the fuel/ oxidant ratio. For this
reason, acetylene tanks should be replaced when the cylinder pressure drops to
about 600 kPa (85 psig).
Acetylene may react with copper, silver or mercury to form a
potentially explosive compound. Never use copper tubings or fittings
for acetylene gas connections. the use of stainless steel tubings and
fittings is recommended.
Caution
Failure to change the acetylene cylinder before the cylinder pressure drops
below 600 kPa (85 psig) may cause damage to valves or tubing within the
burner gas control system due to high acetone carryover. Such damage
from acetone is not covered by instrument warranties.
!
Warning