The installation positions of pressure measurement points on horizontal or inclined pipelines should comply with the following provisions:
1. When measuring gas pressure, the measurement point should be installed on the upper half of the pipeline. 2. When measuring liquid pressure, the measurement point should be installed within the range of 0-45° below the horizontal centerline of the pipeline. 3. When measuring steam pressure, the measurement point should be installed on the upper half of the pipeline or within the range of 0-45° below the horizontal centerline of the pipeline.
For the installation of throttling devices on horizontal or inclined pipelines, when the fluid is gas or liquid, the position of the pressure tapping point should comply with the provisions of clauses 1 and 2 of article 4.3.2 of this specification.
For the installation of throttling devices on horizontal or inclined steam pipelines, the position of the pressure tapping point should be within the range of a 45° angle from the horizontal centerline on the upper half of the pipeline.