KROHNE OPTIMASS with MFC 05x EN - Manual (Page 26)

Installation and Operating Instructions OPTIMASS 25
1.3.4 Secondary Pressure containment
The OPTIMASS 3000 (7100) meters are supplied with secondary pressure containment as standard.
Allowable maximum secondary containment pressures are 30 bar at 20°C or 435 psig at 70°F, and is de-
rated as follows :
20 °C 50°C 100°C 150°C
30 bar 28.5 bar 26.1 bar 24 bar
The de-rating is based on the reduction of material strength with temperature for 316L (W No. 1.4404)
material from DIN 17456.
Heating jacket is rated to 10 bar at 150°C or 145 psig at 300°F.
If heating jacket fitted, secondary containment is limited to 10 bar at 150°C or 145 psig at 300°F. This is
because the jacket is fitted inside of the secondary containment dome.
If meter operating pressure is higher than the secondary containment allowable pressure then a relief or
bursting disk option (fitted in the dome) MUST be ordered. In this case the meter data plate is stamped
with maximum pressure rating (at maximum operating temperature) of the connection or the primary tube
(whichever is the lower).
Note:
Burst disc options are not available in combination with a heating jacket.
1.3.5 Pressure de-rating
Meter data plates are stamped with maximum pressure rating (at max. operating temperature) of
connection, primary tube or secondary pressure containment (whichever is the lower). Higher pressures
may be possible at lower temperatures.
Stainless Steel tubes: 150 bar at 80°C or 2175 psi at 175°F
50 bar at 150°C or 725 psi at 300°F
Hastelloy C22 tubes: 150 bar at 150°C or 2175 psi at 300°F
(no de-rating required)
Pressure Derating
Pressure/temperature de-rating for SS and Hast C22
all process connections except hygienic
0
20
40
60
80
100
120
140
160
-50 -30 -10 10 30 50 70 90 110 130 150
Temperature in deg.C
Pressure i
n
bar
316 SS tube
Hast C22 tube
30 bar pressure
containment
Note:
All operating pressures above the
secondary pressure containment
pressure will have a bursting disk fitted
to the secondary containment dome.