Parr Instrument 1108P - Manual (Page 4)

P a r r I n s t r u m e n t C o m p a n y 4
1108P Oxygen Combustion Vessels
Operating the 1108P Oxygen
Combustion Vessel
Precautions
Combustion with oxygen in a sealed bomb is a very
effective and reliable method for releasing all heat
energy obtainable from a sample and for preparing
hydrocarbon compounds and carbonaceous materi-
als for analysis, but there are certain precautions
which must always be observed when using this
equipment. In particular:
• Do not overcharge the bomb with too much
sample or with a sample which might react with
explosive violence.
• Do not overcharge the bomb with too much
oxygen. The initial charging pressure should not
exceed 40 atm (590 psig).
• Do not fire the bomb alone on an open bench
without providing a protective cooling medium.
The bomb should be completely submerged in
water during firing.
• Do not fire the bomb if gas bubbles are released
from any point on the bomb when it is sub-
merged in water.
• Do not ignite a volatile sample without using
one of the sealed sample holders described on
pages 8-10.
• Stand away from the bomb during and do not
handle the bomb for at least 6 minutes after fir-
ing.
• Keep the bomb in good condition at all times.
Any parts that show signs of weakness or dete-
rioration must be replaced promptly.
• Read the maintenance and safety instructions
beginning on page 12 before starting to use the
bomb, and urge all operating personnel to re-
read these instructions often.
• Screw caps and cylinders are stamped so that
each cylinder and screw cap can be identified as
a matched set. We recommend that you maintain
the match of cylinders and screw caps for your
safety and ease of use.
Special Alloy Construction
The standard 1108P Oxygen Combustion Vessel is
made of a special niobium-stabilized stainless steel
selected for it’s excellent resistance to the mixed
nitric and sulfuric acids generated in a bomb com-
bustion. It is a superior alloy which will withstand
the conditions generated in almost all fuel testing
applications, yet neither it nor any other stainless
steel will resist the corrosive atmospheres pro-
duced when burning samples containing halogen
compounds. For these applications, Parr offers the
1108PCL described below. It should be noted that
all instructions for the 1108P apply equally to the
1108PCL as well.
A Chlorine-Resistant Bomb
The 1108PCL is the same as the standard 1108P
model, but with a head and cylinder made of an
alloy with superior corrosion resistance to the free
chlorine and halogen acids released when burn-
ing chlorinated samples. Users who analyze waste
materials and combustible solvents are urged to
select the 1108PCL instead of 1108P for its longer
service life under extreme corrosive conditions.
Bomb maintenance is also improved. In most cases,
1108PCL Oxygen Combustion Vessels returned to the
factory for scheduled maintenance can be restored
to optimum finish by polishing instead of having to
rebore the cylinder to remove pits.
1108BP Oxygen Combustion Vessel
The 1108BP and 1108BPCL Combustion Vessels are
identical to the 1108P and 1108PCL models except
for the screw cap and cylinder. The 1108BP and
1108BPCL have a heavy duty screw cap allowing for
higher energy release per sample. The cylinder has
been adapted to comply with Indian Standard IS 1350.
Other Special Purpose Bombs
Although the 1108P and 1108PCL will handle a broad
range of test samples, Parr also offers other spe-
cial purpose combustion bombs, including: a high
pressure bomb for explosives, an oversize bomb
for large samples and a semi-micro bomb for small
samples. Separate operating instructions are issued
for these special bombs.