Best practices for Differential Pressure Flow measurement instrument installation

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Flow measuring instrument installation guideline

1.Keep impulse piping as short as possible

2.For liquid service,slope the impulse piping at least 1 inch per foot upward from the transmitter towards the process connection.

3.For gas service,slope the impulse piping at least 1 inch per foot downward from the transmitter towards the process connection.

4.Avoid high point in liquid lines and low points in gas line.

5.Make sure both impulse legs are at same temperature.

6.Use impulse piping large enough to avoid friction effects and blockage.

7.Vent all gas from liquid piping legs

8.When measuring a fluid,fill both piping legs to the same level.

9.when purging make the purge connection to the process taps and purge through equal lengths of the same size pipe.Avoid purging through transmitter.

10.Keep corrosive or hot process material out of direct contact with the sensor modules and flanges.

  1. Prevent sediment deposits in the impulse piping.

12.keep the liquid head balanced on both legs of the impulse piping.

  1. Avoid conditions that might allow process fluid to freeze within the process flange.

Liquid Flow measurement Best Practice

Place taps to the side of the line to prevent sediment deposits on the transmitter’s process isolator.

Mount the transmitter beside or below the taps so gases can vent in to the process line.

Mount drain/vent valve upward to allow gases to vent.

Gas Flow measurement Best practices

Place taps in the top or side of the line.

Mount the transmitter beside or above the taps so liquid will drain into the process line.

Steam Flow Measurement Best Practices

Place taps to the side of the line.

Mount the transmitter below the taps to ensure that the impulse piping will stay filled with condensate.

Fill impulse lines with water to prevent the steam from contacting the transmitter directly and to ensure accurate measurement at startup.