Parr Instrument Series 4520 - Manual (Page 13)

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4520 Bench Top Reactors Parr Instrument Company
HOW TO USE THE VESSEL
PTFE Gasket or O-ring Seal
It is important to examine the main seal
of the head and cylinder before running any
experiments. Make certain that the gasket
or O-ring are in good condition. The seal
should not have any nicks or be hardened,
discolored or deformed. Examine the
mating surfaces of both the head and
cylinder to be sure they are clean and free
from burrs.
Fixed Head Vessel Installation
Lower the heater assembly and swing it to
the left for clearance while installing the
vessel assembly. Open the hinged retainer
bar and slide the square lip of the head into
the support plate. Close the hinged retainer
bar. Place the cylinder in the lift cup and
raise the cylinder up to the head. Place the
split rings around the head and cylinder and
close the split ring latches. Follow the bolt
tightening procedure below.
Moveable Head Vessel Installation
Lower the heater assembly and swing it
to the left for clearance while installing the
vessel assembly. With the vessel on the
countertop, mount the head on the cylinder.
Place the split rings around the head and
cylinder. Raise the drop band around the
split ring. Tighten the drop band bolt finger
tight. Follow the bolt tightening procedure
below before installing the vessel assembly
into the support frame. The split ring closure
rests on the top of the support plate
Sealing Vessels with PTFE Gaskets
First, hand tighten the six bolts. Then
using the open-ended wrench supplied with
the system. Proceed in a criss-cross pattern
to tighten the bolts to 25 ft/lbs. This can be
achieved by applying a firm but hard pull to
each bolt. Allow the vessel to stand for
about five minutes after the initial tightening
procedure to allow for the flow of the PTFE
gasket under load, then retighten the bolts.
Sealing Vessels with O-ring Seals
Moveable head vessels with O-ring seals
include a split ring and a drop band. Place
the split rings around the head and cylinder.
Raise the drop band around the split ring
placing the band so that the bolt will tighten
into the dimple on the split ring. Tighten the
drop band bolt finger tight.
Fixed head vessels with O-ring seals
include a split ring with latches. Place the
split rings around the head and cylinder.
Close the latches.
Gas Inlet / Liquid Sampling Valves
These reactors include a double valve
assembly with a common dip tube. This
arrangement allows the introduction of gas
into the liquid level as well as the ability to
take samples while the vessel is under
pressure. The A146VB angle pattern valve
at the top is the gas inlet position. The
A122VB straight needle valve mounted on
the side of the 208HC10 adapter is the liquid
sampling valve.
Gas Connections
The A495HC pressure hose is made of
reinforced Nylon which can be used at
ambient temperature for all non-corrosive
gases at pressures up to 2500 psig. This
hose is furnished with a male “A” socket
connection which will attach to the 420HC
coupling installed on the gas inlet valve
above the internal dip tube. The other end
includes a ¼” NPT male bushing with a
alternate 1/8” NPT male thread underneath
for attachment to the gas tank valve.
To attach the hose, pull back the nut,
rotate the sleeve back as far as it will go
toward the nut, insert it into the coupling and
then tighten the compression nut firmly.
Note: This assembly acts like a pipe union,
allowing the hose to remain stationary while
the joint is tightened.