Labconco Protector Controlled Atmosphere Glove Boxes 5080102 - Manual (Page 11)

INSTALLATION
12
Pressure Relief Bubbler
The Pressure Relief Bubbler operates with vacuum pump oil having a specific gravity of
0.87. The user must determine the compatibility of substances used in the glove box with vacuum
pump oil.
The Pressure Relief Bubbler is designed to relieve positive and negative pressure in the
glove box. The relief pressure point is established by the amount of oil that is poured into the
bubbler at time of installation. The oil level may be varied to relieve pressure at any point between
± 10" H
2
O. Recommended relief pressure is 7" H
2
O.
The bubbler operates on the same principle as a U-tube manometer. When pressure or
vacuum is applied to the bubbler, the oil level in one column will decrease as it increases in the
other column. The vertical difference between the two oil column levels indicates the pressure or
vacuum applied to the bubbler. When this pressure becomes sufficient to lower the oil level in one
of the columns to the level of the return bend, any additional pressure or vacuum is vented through
the full column by oil bubbling. The accumulator at the top of each column traps oil droplets in
the relief pressure air stream and prevents them from escaping the bubbler. The user must
determine whether the exhaust port of the bubbler should be filtered or vented outside the
laboratory.
CAUTION NOTES:
A. Failure to install the pressure relief bubbler may result in equipment damage or personal
injury due to inadvertent over pressurization or excessive decompression of the glove box.
B. If the bubbler exhaust is to be filtered or vented outside the laboratory, it is the user’s
responsibility to ensure that any additional airflow restriction is less than 0.5" H
2
O static
pressure.
C. In case of excessive decompression, the user must determine whether laboratory
atmosphere entering the glove box could result in fire or explosion hazards.
The Pressure Relief Bubbler with mounting hardware and a 1-liter bottle of vacuum pump
oil is packaged in a separate carton located above the transfer chamber. The bubbler must be
installed to avoid equipment damage or personal injury. Install according to the following steps
and refer to Figure 5.
1. Attach hanger bracket to top back edge of cabinet with #8 x 1/2" screw. Leave screw loose
to allow adjustment later.
2. Attach bubbler to hanger bracket with the nut, washer and _-20 screw (installed on the
upper cross member of the bubbler). Leave the nut untightened for later adjustment.
3. Insert lower end of bubbler into the Swagelok fitting. Make sure the bubbler tube end and
brass conical shaped ferrule enters the fitting freely with no binding. Thread the Swagelok
nut onto the fitting by hand until hand-tight. Hold the fitting with a wrench and tighten the
nut an additional _ turn.