Parr Instrument Series 4540 - Manual (Page 6)

4540 High Pressure Reactor System
P a r r I n s t r u m e n t C o m p a n y 6
FIXED HEAD OR REMOVABLE HEAD DESIGN
Parr Series 4540 High Pressure Reactors are furnished with two structural options in addition to the size,
pressure range, stirrer motor, controller and similar options. These are:
Fixed Head Moveable Head
Vessel Head Design
There is no difference in the pressure or temperature
limits or basic operating instructions based upon the
fixed head or movable vessel options. There are dif-
ferences in the design of the stand components which
adapt the vessels to the support system.
In the fixed head design, the head of the vessel may
remain fixed in the reactor support stand. All attach-
ments to the head, gas and liquid feed and discharge
lines, cooling water, vapor take-off and condenser,
thermocouple, and any electrical leads can remain
permanently in place. The reactor is opened by
removing the cover clamp sections and lowering the
cylinder away from the head.
In the removable head vessel design, all connections to
the head are removed to allow the vessel to be opened.
PTFE Flat Gasket
The flat gasket is held in a recess in the vessel
head and a machine pilot on the cylinder closes the
recess to completely contain the gasket. The split
ring closure used with this gasket has eight com-
pression bolts which must be tightened to develop
the loading on the gasket.
Maximum temperatures of a given system are
dependant upon the material of construction and
type of seal. Other accessories may limit operating
temperature. The PTFE flat gasket can be used to
operating temperatures as high as 350 °C.
Metal gaskets can be furnished for special applica-
tions. The metal gaskets are not interchangeable
with the flat gasket design, but require special
grooves machined into the head and cylinder.
Parr recommends the PTFE flat gaskets for most
applications.