Gauge Pressure Measurement; Absolute Pressure Measurement; Mounting A Diaphragm-Seal(S)-Equipped Transmitter - ABB S26 Series Operating Instruction

4.6 Gauge pressure measurement

A gauge pressure transmitter with a remote seal can be used
for measurement of pressure in either a process pipe or tank.
Locate the remote seal in the side or top of the pipe to avoid
collection of sediment on the seal diaphragm.
4.6.1 Pressure Service
When the operating pressure range has a minimum value
above atmospheric pressure (0 psig), the transmitter can be
placed in any convenient location, either at the same elevation
as the remote seal, above or below the seal.
4.6.2 Vacuum Service
When the operating process pressure range includes pressures
below atmospheric, it is essential that the transmitter be
located below the elevation of the seal element to ensure that
the pressure in the transmitter body is always greater than 0
psia. The recommended minimum distance between the
transmitter datum line and the seal datum line is 30cm (1ft).
Figure 13: Possible installation for gauge and absolute pressure measurement
Note. The minimum value is to be above the atmospheric pressure
(0 psig). Transmitter can be placed in any convenient location.

4.7 Absolute pressure measurement

An absolute pressure transmitter with a remote seal can be
used for measurement of absolute pressure in either a process
pipe or tank. Locate the seal element in the side or top of the
pipe to avoid collection of sediment on the seal diaphragm.
When the operating absolute pressure range has a minimum
value above atmospheric pressure (nominally 14.7 psia), the
transmitter can be placed in any convenient location, either at
the same elevation as the remote seal, above the seal, or
below the seal. When the pressure range includes pressures
below atmospheric, the transmitter datum line must be below
the elevation of the seal element to ensure that the pressure in
the transmitter body is always greater than 0 psia. The
recommended minimum distance between the transmitter
datum line and the seal datum line is 30 cm (1ft).
4.8 Mounting a diaphragm-seal(s)-equipped
transmitter
The transmitter with remote seals can be mounted on a 60 mm
(2 in.) horizontal or vertical pipe using the optional pipe
mounting bracket available with all 2600T series transmitters.
Direct-mount seal transmitters, instead, can be installed
without the bracket kit since a mating flange is generally
provided.
2600T Series Pressure transmitters | OI/S266-EN Rev. B 13