5.4.1
Remote seal with capillary line
Notes
● Do not transport the measuring assembly (pressure transmitter, flange and capillary line) to
the capillary line.
● Do not bend the capillary lines. Otherwise there may be a leakage risk and the set-up time
of the measuring system is increased.
● A mechanical overload at the connection points between capillary line and remote seal or
between capillary line and pressure transmitter will lead to potential bending or breaking.
● Wind capillary lines that are too long with a radius of at least 300 mm.
● Fasten the capillary line such that there are no vibrations.
● Permissible height differences:
– In the case of remote seal measuring systems with silicon, glycerin or paraffin oil filling,
the height difference of H
1max.
= 7 m must not be exceeded.
– When halocarbon oil is used as fill fluid, the maximum height difference may only be
H
1max.
= 4 m; see installation type A and installation type B.
If a negative overpressure is observed during measurements, reduce the permissible height
difference.
Installation type for gauge pressure and level measurements (open containers)
+
+
+
X
+
R
Installation type A: Pressure transmitter
above the measuring point
Start of scale value:
p
LRV
= ρ
FL
* g * H
U
- ρ
oil
* g * H
1
Full-scale value:
p
URV
= ρ
FL
* g * H
O
- ρ
oil
* g * H
1
Installing/mounting
5.4 Installation with remote seal
SITRANS P320/P420 with 4 to 20 mA/HART
56
Operating Instructions, 11/2019, A5E44852162-AC