Parr Instrument Series 4560 - Manual (Page 7)

Mini Bench Top Reactors
w w w . p a r r i n s t . c o m 7
Installation
Pressure and Temperature Limits
The working pressure and temperature at which any
reactor or pressure vessel can be used will depend
upon the design of the vessel and the materials
used in its construction. Since all materials lose
strength at elevated temperatures, any pressure
rating must be stated in terms of the temperature at
which it applies. The standard material of construc-
tion for Parr Instrument Company is Type 316 Stain-
less Steel.
Limits for vessels made of other materials and for
other operating temperatures can be obtained from
Parr Customer Service. No attempt should be made
to increase these limits by making alterations or by
substituting components that are not recommended
by the Parr Instrument Company. It must also be
understood that lower pressure and temperature
limits may be required for modifi ed reactors and for
vessels made of special alloys.
Limits for vessels will be determined by the physi-
cal characteristics of the vessel material and will be
prescribed on an individual basis.
The maximum working pressure and temperature
for any vessel is governed by the design of the
vessel and the strength of the material from which
it is constructed. There is also a close relationship
between working pressure and temperature since
the strength of any material will normally fall off
as the temperature is increased. Temperature and
pressure limits are also affected by the physical
properties and temperature limits of the gaskets and
seals used in the vessel, and by any valves, gages or
other fi ttings attached to the vessel. The safe operat-
ing pressure of any system can be no higher than
that of its lowest rated component.
All Parr reactors show the maximum safe operating
pressure and temperature imprinted on the cylinder.
An accompanied restricted operating limit tag and/
or supplemental manual is given when a compo-
nent of the system limits the operation below the
imprinted valves.
Working temperatures up to 225 °C are permissible
in Mini Reactors equipped with fl uoroelastomer
(FKM) O-ring seals. The higher the operating tem-
perature above 200 °C, the shorter the life of the O-
ring will be. Perfl uoroelastomer (FFKM) O-ring seals
have a broad chemical resistance and can be used
to temperatures up to 300 °C. Unfortunately they
are very expensive and will generally be reserved
for unique applications. Ethylene-propylene (EP)
O-rings can be used to 170 °C and are recommend-
ed for applications such as ethers, ammonia and
amines which will rapidly destroy fl uoroelastomer
O-rings.
Pressure Vessel and Temperature Limits
In the standard pressure and temperature setup, the
system must not exceed the following:
Vessel
Material
Maximum
Pressure
Maximum
Temperature
T316SS 3000 psig (200 bar)
350 °C PTFE
Flat Gasket
T316SS 3000 psig (200 bar)
225 °C FKM
O-Ring
T316SS 3000 psig (200 bar)
300 °C FFKM
O-Ring
In the high pressure/high temperature setup, the
system must not exceed the following:
Vessel
Material
Maximum
Pressure
Maximum
Temperature
T316SS (HT) 2000 psig (138 bar) 500 °C Flexible
Graphite Flat
Gasket