Mounting Requirements - Emerson Rosemount WPG Reference Manual

Hardware Installation
March 2016
The best location for the device in relation to the process pipe depends on the process itself.
Use the following guidelines to determine device location and placement of impulse piping:
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2.5.2

Mounting requirements

Liquid flow measurement
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Gas flow measurement
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Steam flow measurement
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Note
For steam or other elevated temperature services, it is important that temperatures do not
exceed 250 °F (121 °C) for devices with silicone fill. For vacuum service, these temperature
limits are reduced to 220 °F (104 °C) for silicone fill.
10
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 device toward the process connection.
For gas service, slope the impulse piping at least 1 inch per foot (8 cm per m)
downward from the device 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 device.
Keep corrosive or hot (above 250 °F [121 °C]) process material out of direct contact
with the sensor module 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.
Place taps to the side of the line to prevent sediment deposits on the process
isolators.
Mount the device beside or below the taps so gases vent into the process line.
Mount drain/vent valve upward to allow gases to vent.
Place taps in the top or side of the line.
Mount the device beside or above the taps so to drain liquid into the process line.
Place taps to the side of the line.
Mount the device below the taps to ensure that impulse piping will remain filled
with condensate.
Fill impulse lines with water to prevent steam from contacting the device directly
and to ensure accurate measurement start-up.
Reference Manual
00809-0100-4045, Rev AB
Hardware Installation