The learning objectives of this section
are to familiarize or personnel involved
in tank atmosphere control operations
with
sampling hoses
hand aspirators
built-in pumps
it is very important to understand that
the quality of the sampling hose can
influence the measured result and that
correct use and maintenance that
important
make sure that the hoses in use on your
ship our of approved quality
examples of hoses which approved
acceptable one teflon in hose neoprene
outer hose this hose is an inner
diameter of 3 millimeters which
corresponds to an inner volume of
approximately 7 cubic centimeters per
meter to town all is a trademark of ms a
this hose is marked tunnel synthetic
rubber sampling line low solvent
absorption anti-static note when used in
an enclosed space adequate electrical
bonding is required the inner diameters
five millimeters which corresponds to an
inner volume of about 20 cubic
centimeters per meter
always ask the supplier for a
certificate showing the authorization it
is very important to use high-quality
hose for the safety of the crew and the
vessel
if the sampling hose gets dirty with oil
on the outside immediately clean it with
a dry cotton rag if the hose is
accidentally dipped in oil and oil is
drawn into the holes discard the holes
because it is very hard to clean
the hand pumps use that often made of
rubber with a volume of 40 cubic
centimeters or more when using long
hoses it is important to know the number
of pump strokes that are necessary for
the gas to reach the instrument the
sampling point
the number of strokes depends on the
length of the hose as well as the inner
diameter of the hose
the number of strokes may vary from six
to fifteen for a hose length of 30
meters depending on the inner diameter
the figures given are based on a pump
volume of 40 cubic centimeters
some types of indicators are fitted with
built-in pumps follow the use
instructions for such pumps
always check the hose instruments and
pumps before use in order to detect any
leakage plugging or contamination follow
the relevant procedure for each
instrument
place the finger on the hose opening and
ensure that the hand pump remains
squeezed flat for about one minute or if
there is a built-in pump the flow
indicator gives an alarm