Parr Instrument Series 3900 - Manual (Page 12)

Hydrogenation Apparatus
P a r r I n s t r u m e n t C o m p a n y 12
Special Instructions for the 3921 Hydrogenator
All instructions given in the preceding sections of
this Manual apply equally to both the 3911 and 3921
Hydrogenators. Both models use the same hydro-
gen tank and valves, but the 3921 apparatus has a
larger and heavier bottle clamp and shaker mecha-
nism to accommodate larger reaction bottles.
Motor and Gear Box
Before starting the motor, replace the uppermost
pipe plug on the gearbox with the blue plastic vent
plug which is furnished. The hole in the vent plug
must point up. See Boston gear instruction sheets
for lubricating instructions.
Bottle Connectors
Attach the valves to the gas tank and connect the
polypropylene tube to the reaction bottle by slid-
ing the tube through the 82CA2 washer and 166CA
retaining ring, then push the tube through the bottle
stopper leaving a projection of about one inch be-
low the stopper. To complete the assembly, set the
bottle on top of the rubber pad in the holder: slide
the tube through the slot in the clamping screw and
tighten the screw fi rmly. Always attach the steel
guard screen to the front of the bottle holder before
pressurizing the bottle.
An 80CA2 spacer must be placed between the
clamping screw and the stopper to compensate for
the difference in bottle heights when using a 1000
mL bottle, Assemble the inlet tube with the 80CA2
spacer and 166CA retaining ring above the stopper
and clamp the bottle in the shaker in the usual man-
ner. The 82CA2 washer is not required when using a
spacer.
Glass Reaction Bottles
The 1000 and 2000 mL reaction bottles (71CA and
72CA) supplied with this apparatus have been
individually pressure tested to 80 psig and 60 psig
respectively. In spite of these tests, the Parr Instru-
ment Company cannot guarantee that these bottles
will not break at lower pressures. The user must
therefore be constantly aware of the hazards in-
volved in handling large volumes of liquids in glass
bottles under pressure, and he must take whatever
precautions he considers necessary to protect him-
self from injury in case a bottle should unexpect-
edly fail. It is recommended that working pressures
in these 1000 and 2000 mL bottles should never
exceed 40 psi and 30 psi respectively. Pressures
should be held below this maximum whenever pos-
sible.
Customer installed location of
Blue Plastic Vent Plug