Parr Instrument Series 5000 - Manual (Page 6)

- 6 -
5000 Series Multiple Reactor System
PRESSURE AND
TEMPERATURE LIMITS
Working pressures up to 3000 psi (207
bar) maximum are permissible in these
reactors when constructed of Type 316
Stainless Steel. Contact Parr Customer
Service if your vessel is not constructed
of T316 Stainless Steel and you are
unsure of the pressure and temperature
limit. No attempt should be made to
increase these limits by making
alterations or by substituting
components which are not
recommended by Parr Instrument
Company. It must also be understood
that lower pressure and temperature
limits may be required for modified
reactors and for vessels made of
materials other than T316 Stainless
Steel. Limits for such vessels will be
determined by the physical
characteristics of the material of
construction and will be prescribed on
an individual basis.
Working temperatures up to 300 °C are
permissible in reactors with a standard
2895HCHA flat PTFE gasket. A PTFE
gasket is the recommended choice for
most applications since the PTFE is
inert to most chemicals and it will
provide good seals under repeated
opening and closing if the gasket
temperature does not exceed 300 °C.
The service life of a PTFE gasket will,
however, be reduced considerably if
used at temperatures close to the
300 °C limit.
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 fittings
attached to the vessel. Obviously, the
maximum safe operating pressure of
any system can be no higher than that
of its lowest rated component.
Working temperatures up to 220 °C are
permissible in reactors equipped with
fluoroelastomer (FKM) O-ring seals.
The higher the operating temperature
above 200 °C, the shorter the life of the
O-ring will be. Perfluoroeleastomer
(FFKM) O-ring seals have a broad
chemical resistance and be used to
temperatures up to 275 °C.
Unfortunately they are very expensive
and will generally be reserved for unique
applications. Ethylene-propylene (EP)
O-rings can be used to 150 °C and are
recommended for applications such as
ethers, ammonia, and amines which will
rapidly destroy fluoroelastomer O-rings.
The working pressure and temperatures
in these reactors must not exceed the
following maximum limits:
Pressure and Temperature Limits
Vessel
Material Maximum
Pressure Maximum
Temperature
T316SS 3000 psi
300 °C PTFE
Flat Gasket
T316SS 3000 psi
220 °C FKM
O-ring
T316SS 3000 psi
275 °C FFKM
O-ring
T316SS 3000 psi
150 °C EP
O-ring