Emerson Rosemount 3051S Series Reference Manual page 23

Reference Manual
00809-0100-4801, Rev FA
October 2010
Impulse Piping
The piping between the process and the transmitter must accurately transfer
the pressure to obtain accurate measurements. There are five possible
sources of error: pressure transfer, leaks, friction loss (particularly if purging is
used), trapped gas in a liquid line, liquid in a gas line, density variations
between the legs, and plugged impulse piping.
The best location for the transmitter in relation to the process pipe depends on
the process itself. Use the following guidelines to determine transmitter
location and placement of impulse piping:
• Keep impulse piping as short as possible.
• For liquid service, slope the impulse piping at least 1 inch per foot
(8 cm per m) upward from the transmitter toward the
process connection.
• For gas service, slope the impulse piping at least 1 inch per foot (8 cm
per m) downward from the transmitter toward the process connection.
• Avoid high points in liquid lines and low points in gas lines.
• Make sure both impulse legs are the same temperature.
• Use impulse piping large enough to avoid friction effects and blockage.
• Vent all gas from liquid piping legs.
• When using a sealing fluid, fill both piping legs to the same level.
• When purging, make the purge connection close to the process taps
and purge through equal lengths of the same size pipe. Avoid purging
through the transmitter.
• Keep corrosive or hot (above 250 °F [121 °C]) process material out of
direct contact with the SuperModule and flanges.
• Prevent sediment deposits in the impulse piping.
• Keep the liquid head balanced on both legs of the impulse piping.
• Avoid conditions that might allow process fluid to freeze within the
process flange.
Optional Advanced HART Diagnostics Electronics
Statistical Process Monitoring (SPM) provides statistical data (standard
deviation, mean, coefficient of variation) that can be used to detect process
and process equipment anomalies, including plugged impulse lines, air
entrainment, pump cavitation, furnace flame instability, distillation column
flooding and more. This diagnostic allows you to take preventative measures
before abnormal process situations result in unscheduled downtime or
rework.
Power Advisory diagnostic proactively detects and notifies you of degraded
electrical loop integrity before it can affect your process operation. Example
loop problems that can be detected include water in the terminal
compartment, corrosion of terminals, improper grounding, and unstable power
supplies.
The enhanced EDDL Device Dashboard presents the diagnostics in a
graphical, task-based interface that provides single click access to critical
process/device information and descriptive graphical troubleshooting.
Rosemount 3051S Series
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