VEGA VEGADIF 65 Chemical seal CSB - Manual (Page 11)

11
3 Planning instructions for isolating systems
Chemical seal CSB • for VEGADIF 65
36133-EN-130417
90 %
100 %
t
T90%
1
2
Fig. 9: Presentation of the step response time (T90)
1 Pressure jump
2 Output signal
For minimisation of the step response time, you have to following
options:
•
Bigger capillary inner diameter
•
Shorter capillaries
•
Filling oil with lowest viscosity
3.4 Installation position
When the pressure transmitter is mounted above the lower chemical
seal, the max. height difference H1 according to the following illustra-
tion may not be exceeded. The value depends on the density of the
filling oil and the smallest pressure that may act on the chemical seal
of the plus side (empty vessel).
Typical values for H1 are 7 m with silicone oil and 4 m with halocarbon
oil.
+ –
+
–
H1
– +
Fig. 10: Max. height when mounting above the lower chemical seal
In vacuum applications, the pressure transmitter should be mounted
at the same height as or below the lower chemical seal. By doing
Minimization of the step
response time
Standard applications
Vacuum applications