Parr Instrument Series 5500 - Manual (Page 7)

Compact Micro Reactors
w w w . p a r r i n s t . c o m 7
Installation
Pressure and Temperature Limits
Working pressures up to 3000 psig (200 bar)
maximum are permissible in these micro reactors
when constructed of Type 316 Stainless Steel and
equipped with a magnetic stirrer drive. Pressure
limits for reactors made of materials other than
Type 316 Stainless Steel can be obtained from Parr
Customer Service. No attempt should be made to
increase these limits by making alterations or by
substituting components which are not recom-
mended 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 special. 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 350 ºC are permissible
in micro reactors equipped with a standard, flat
gasket, No. 429HC2, made of PTFE fluoropolymer
resin. A PTFE gasket is the recommended choice
for most applications since the PTFE resin is inert to
most chemicals and it will provide good seals under
repeated opening and closing if the gasket tempera-
ture does not exceed 350 ºC. The service life of a
PTFE gasket will, however, be reduced considerably
if used at temperatures above 300 ºC. For better ser-
vice in the 300 ºC to 350 ºC operating range Parr rec-
ommends a flexible graphite gasket, No. 429HC2KL.
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 safe operating pressure of any system can be no
higher than that of its lowest rated component.
Working temperatures up to 225 ºC are permissible
in micro reactors equipped with fluoroelastomer
(FKM) O-ring seals. The higher the operating tem-
perature above 200 ºC, the shorter the life of the O-
ring will be. Perfluoroelastomer (FFKM) O-ring seals
have a broad chemical resistance and can be used
to temperatures up to 300 ºC. Unfortunately they
are very expensive and will generally be reserved
for unique applications. Ethylene-propylene (EP)
O-rings can be used to 170 ºC and are recommend-
ed for applications such as ethers, ammonia and
amines which will rapidly destroy fluoroelastomer
O-rings.
The working pressure and temperature in these 25,
50 & 100 mL reactors must not exceed the following
maximum limits:
Pressure and Temperature Limits
Bomb
Material
Maximum
Pressure
Maximum
Temperature
T316SS 3000 psig 350 ºC PTFE Flat Gasket
T316SS 3000 psig 225 ºC FKM O-Ring
T316SS 3000 psig 300 ºC FFKM O-Ring