Remote Seal And Differential Pressure Flow Measuring Systems; Remote Seal; Differential Pressure - Flow Measuring Systems - Siemens SITRANS P Operating Instructions Manual

Description

4.6 Remote seal and differential pressure flow measuring systems

4.6 Remote seal and differential pressure flow measuring systems
4.6.1

Remote seal

● A remote seal measuring system comprises the following elements:
– Remote seal
– Transmission line, e.g. capillary line
– Pressure transmitter
● The measuring system based on a hydraulic principle is used to transfer pressure.
● The capillary line and the remote seal diaphragm are the most sensitive components in the
remote seal measuring system. The material thickness of the remote seal diaphragm is only
∼ 0.1 mm.
● The smallest of leakages in the transmission system leads to the loss of transmission fluid.
● The loss of transmission fluid results in inaccuracies in the measurement and failure of the
measuring system.
● In order to avoid leaks and measuring errors, please observe the installation and
maintenance instructions in addition to the safety notes.
See also
Installation with remote seal (Page 54)
4.6.2

Differential pressure - flow measuring systems

A differential pressure flow measuring system consists of the following components:
● Primary element, e.g. orifice or averaging pitot tube
● Shutoff fitting, valve manifold
● Pressure transmitter
Application examples for differential pressure and flow with primary elements, refer to section
Differential pressure and flow rate (Page 94).
You can find additional information on primary elements in the associated instructions under:
Manuals for SITRANS FP (https://support.industry.siemens.com/cs/ww/en/ps/26040/man)
40
Note
Malfunction of the remote seal measuring system
If you separate the components of the remote seal measuring system, this results in
malfunctioning of the system.
Do not separate the components under any circumstances.
SITRANS P320/P420 with 4 to 20 mA/HART
Operating Instructions, 11/2019, A5E44852162-AC