Installation In Still Pipe/Chamber - Emerson Rosemount 3308A Reference Manual

Installation
August 2017
3.3.4

Installation in still pipe/chamber

General chamber considerations
A chamber or pipe installation is the preferred option due to the increase in stability and performance of
the transmitter. When selecting a smaller diameter chamber or pipe (such as 2-in.) a flexible probe is not
suitable due to the chance of it coming into contact with the walls, and relatively large side inlets may
interfere with the signal.
When gas lift and/or turbulence may occur (e.g. boiling hydrocarbons), a 3- or 4-in. chamber/pipe
diameter is recommended for maximum measurement reliability. This is especially true in high pressure
and high temperature installations.
Rosemount 9901 Chamber
Rosemount 9901 allows external mounting of process level instrumentation. It supports a variety of
process connections, and optional drain and vent connections. The Rosemount 9901 chamber is
designed to the ASME B31.3 standard, and is Pressure Equipment Directive (PED) compliant. Use option
code XC to order together with the Rosemount 3308 Series Transmitters.
Figure 3-7. Side-and-Side and Side-and-Bottom Chambers
Side-and-side
dimension
The probe length to use for a Rosemount 9901 chamber can be calculated with this formula:
Side-and-side dimension:
Probe length=Centre-to-centre dimension + 19 in. (48 cm)
Side-and-bottom dimension:
Probe length=Centre-to-centre dimension + 4 in. (10 cm)
Use a centering disc the same diameter as the chamber if the probe length >3.3 ft. (1 m). See
on page 28
For additional information, see the Rosemount 9901 Chamber for Process Level Instrumentation
Data Sheet.
20
PRELIMINARY
Side-and-bottom
dimension
for which disc to use.
Reference Manual
00809-0100-4308, Rev CA
Table 3-5
Product
Installation