Fisher-Rosemount 3095FT, Руководство пользователя

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Rosemount Model 3095FT HART Flow Transmitter
2-8
Taps For gas flow measurement, place taps in the top or side of the line and
mount the transmitter beside or above the taps so liquid will drain into
the process line.
Impulse Piping The piping between the process and the transmitter must accurately
transfer the pressure to obtain accurate measurements. In this
pressure transfer, three possible sources of error can occur: leaks,
friction loss, and liquid in the impulse line.
Consider the following general rules in determining flow transmitter
location and placement of impulse piping:
• Keep impulse piping as short as possible.
• Slope the impulse piping at least one inch per foot (8 centimeters
per meter) downward from the transmitter toward the process
connection.
• Avoid low points in gas lines.
• Use impulse piping large enough to avoid friction effects and
prevent blockage.
• Keep corrosive or hot (above 185 °F (85 °C)) process material out
of direct contact with the sensor module and flanges.
• Prevent sediment deposits in the impulse piping.
• Avoid conditions that might allow process fluid to freeze within
the process flange.
Environmental
Considerations Mount the transmitter to minimize ambient temperature changes.
Section 7 - Specifications and Reference Data lists the transmitter
temperature operating limits. Mount the transmitter to avoid vibration
and mechanical shock, and to avoid external contact with corrosive
materials.
Access Requirements When choosing an installation location and position, take into account
the need for access to the transmitter.
Process Flange Orientation
The process flanges must be oriented to enable process connections to
be made. In addition, consider the possible need for a testing or
calibration input.
Housing Rotation The electronics housing may be rotated to improve field access to the
two compartments. To rotate the housing less than 90 degrees, release
the housing rotation set screw and turn the housing not more than 90
degrees from the orientation shown in Figure 2-6 on Page 2-7. To rotate
the housing greater than 90 degrees, follow steps 1–6 of the
disassembly procedure on page 5-10.
Drain/vent valves must be oriented so that process fluid is
directed away from technicians when the valves are used.
Rotating the housing greater than 90 degrees without
performing the disassembly procedure may damage the
Model 3095FT sensor module.