ABB 266CSH - Fill Level Measurement on the Steam Boiler (Drum Water Level)

30 266CRH / 266CRT, 266CSH / 266CST MULTIVARIABLE PRESSURE TRANSMITTER | OI/266CXX/MODBUS-EN REV. A
… 6 Installation
… Mounting recommendations
Fill level measurement on the steam boiler
(drum water level)
H High pressure side
L Low pressure side
1 Gas
2 Liquid
3 Condensate vessel
Figure 22: Level measurement on the steam boiler
• Mount the transmitter at the same height or below the
lowest level to be measured.
• Connect the high pressure side ‘+’ of the transmitter to the
bottom of the tank.
• The low pressure side ‘–’ of the transmitter up at the tank.
Above the maximum level, connect using a condensate
vessel.
• Use the condensate vessel to ensure that the impulse line of
the low pressure side is always filled with liquid (condensate)
at a constant height.
Temperature measurement
• Mount the temperature sensor in the downstream pipe of
the primary element.
• Consider the downstream straight pipe requirements.
• If there is a significant difference between the temperature
of the measuring medium and the ambient temperature, the
measuring error caused by heat conduction must be
minimized by insulating the installation location accordingly.
• Use class ‘A’ sensors to maximize accuracy.
• The lengths of the protective tubes should be 15 to 20 times
the diameter of the protective tube for gas measurements
and 3 to 5 times the diameter of the protective tube for
liquid measurements.