Maximum pressure
and temperature
ratings for vessels
constructed of alloys
other than T316SS
will be computed
and assigned by the
Parr Engineering
Department.
T
he maximum pressure and temperature at
which any reactor or pressure vessel can be
used will depend upon the design of the vessel,
its material of construction, and other components
integral to its design. Since all materials lose
strength at elevated temperatures, any pressure rat-
ing must be stated in terms of the temperature at
which it applies. The listings shown in this catalog
show the maximum allowable working pressure
(MAWP) for each vessel in pounds per square inch
(psi) and in bar at the maximum rated temperature
for that particular design when that vessel is
constructed of Type 316 Stainless Steel. Maximum
pressure and temperature limits for vessels con-
structed of other alloys are computed and assigned
by the Parr Engineering Department in accordance
with all applicable regulations.
Lower operating temperatures sometimes
permit higher working pressures. For example, the
4560HT High Temperature reactors are rated at
2000 psi (138 bar) maximum pressure and 500 °C
maximum temperature. Standard 4560 reactors are
rated at 3000 psi (200 bar) maximum pressure at
350 °C maximum temperature.
One should not assume that any vessel being
operated at a lower temperature can be used at
pressures exceeding the rated MAWP. Factors other
than the material strength of the vessel wall may
well be the constraint controlling the rating. Other
factors that can limit the pressure and temperature
ratings are the closures design, the magnetic drive,
the type of seal, the choice of other components
used, as well as the material of construction.
The maximum operational temperature of some
materials is much lower than what is permissible
with stainless steel as shown in Table II. Users are
encouraged to contact the Parr Customer Service
Department with any questions.
Materials of Construction
Maximum Temperature
T316/316L Stainless Steel
600 °C
Alloy 20
oy
427 °C
Alloy 400
482 °C
Alloy 600
600 °C
Alloy B-2
427 °C
Nickel 200
316 °C
Titanium Grade 2
316 °C
Titanium Grade 4
316 °C
Zirconium Grade 702
371 °C
Zirconium Grade 705
371 °C
Table II
Maximum Allowable Temperatures
Multiple factors are involved
in safely calculating the
maximum working pres-
sures and temperatures of
Parr Pressure Vessels and
Reactors. Please contact Parr
Customer Service Department
for more information and to
assist you in making the
correct purchase decision.
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D e s i g n F e a t u r e s
Pressure and Temperature Limits
