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5.
Place the freeze heads on the pipe and secure by tightening the knobs evenly,
using hex head wrench provided, to give a firm but not over tight hold. (Fig. 2)
6.
Push each injector into the bore of the
freeze head until it is completely
inserted and resting against the stop,
then turn clockwise one quarter turn to
lock in place. (Fig. 3).
Operation
1.
The liquid in the pipe can only be frozen
when it is no longer flowing. All pumps must
therefore be stopped and no liquid allowed to
escape from the pipe. Allow water to cool to
room temperature before freezing.
2.
Fully open the cylinder valve. The amount
of carbon dioxide required is controlled
automatically. The liquid carbon dioxide
expands in the injector and forms dry ice
inside the freeze head with a temperature of
-110 F ° (-79 ° C) and freezes the liquid
within the pipe.
3.
After a brief period, frost will form on the pipe in the vicinity of the freeze heads.
(See table) If frost does not form in accordance with time given in the table, then
this indicates that the liquid within the pipe is still flowing or the water is too warm.
(Check that all pumps have been switched off and prevent any removal or outflow
of liquid)
4.
While work is in progress, the flow of carbon dioxide refrigerant must be
maintained. To ensure a sufficient supply of refrigerant is available, a stand-by
cylinder is suggested. The only way to determine the amount of remaining carbon
dioxide is to weigh the cylinder. If it is necessary to change the cylinder during
work, it is essential that this procedure should be compete within 7 minutes to
prevent the ice pack from melting.
5.
Once work is complete, close the cylinder valve and wait until the pressure in the
spiral hoses has returned to normal before removing them from valve. Once the
ice pack has completely melted , carefully unscrew and remove the injector at the
end of the spiral hoses from the freeze head, then remove the freeze head from
the pipe.
3
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