HP 11744195 - Manual (Page 13)

Chart Environmental Chambers System Installation
suction into the blower in the back wall of the chamber and discharge from the top of the
chamber.
❏ Liquid Nitrogen Plumbing
Along with the electrical power, bring in the LN
2
service from the top or the back of the
chamber for easy access around the chamber. The connection point is at the solenoid
valve on the back wall of the chamber. The nitrogen then flows through the valve and
then enters the chamber to supply liquid nitrogen to the nozzle inside the plenum. The
location of the liquid nitrogen inlet is dimensioned on the O&D drawing at the end of this
manual.
Liquid nitrogen
solenoid valve
Gaseous nitrogen
exhaust connection.
A line relief valve should be installed between the LN
2
connection on the chamber (the
solenoid valve) and the first manual shut-off valve upstream from this connection in the
nitrogen pipe system. This relief valve should be rated at a pressure less than 175 psig,
or the lowest pressure rated component in the system. This relief valve is not included
with the system and should be taken care of at installation.
❏
Exhaust Gas Plumbing
The exhaust gas of the chamber should be plumbed to the outside of the building. No
fans or restrictions should be placed in this line. Any fans or restrictions will decrease
system performance.
It is important to vent the system to the outside of the building for safety reasons. If the
system is not vented to the outside of the building, there is a risk of an oxygen-depleted
atmosphere in the area surrounding the chamber.
The vent piping should also be well insulated to prevent moisture present in the air from
condensing/freezing on the outside surface of the exhaust pipe. The exit of the exhaust
piping should be configured to prevent any water, rain, etc from flowing back into the
chamber’s exhaust system. Any water present in the system may form ice and break the
cooling heat exchanger.
8