Automated instrumentation installation rules

Automated instrumentation installation rules

a), temperature source component

1. The installation position of the temperature source component should be selected in a place where the temperature of the medium is sensitive and representative. It should not be selected in the vicinity of the resistance component such as the valve and the medium flow velocity is at a dead angle and the vibration is large.
2. The location of the thermocouple to take the source component should be away from strong magnetic fields.
3. When installing perpendicular to the process management channel, the axis of the source component should be perpendicular to the axis of the process pipe.

4. When installing at the corner of the process pipe, it is better to reverse the flow direction of the medium. The axis of the source component should coincide with the axis of the process pipe.
5. When installing obliquely with the process pipeline, it is advisable to oppose the flow direction of the medium, and the axis of the source component should intersect with the axis of the process pipeline.

b), pressure source parts
1. The installation position of the pressure source component should be selected where the medium flow rate is stable.
2. When the pressure source component and the temperature source component are on the same pipe segment, they should be installed on the upstream side of the temperature source component.
3. When measuring the pressure of turbid medium with dust, solid particles or sediment, the source part should be installed obliquely upwards. On the horizontal process pipeline, the flow should be smooth and installed at an acute angle.

4. When measuring the pressure of liquid, vapor and condensable gas at a temperature higher than 60 °C, the source part should have a ring or U-shaped condensation bend.
5. When measuring the gas pressure, the pressure port is in the upper part of the process pipe.
6. When measuring the liquid pressure, the pressure tapping port is in the range of 0 to 45 degrees from the horizontal center line of the process pipe in the lower half of the process pipe.

7. When measuring the vapor pressure, the pressure tapping port is in the range of 0 to 45 degrees from the horizontal center line of the process pipe in the upper half and the lower half of the process pipe.

c), flow source component

1. Install the minimum straight pipe section specified by the throttle piece. The inner surface should be clean and free of pits.
2. When installing the thermometer on the upstream side of the throttle, the straight pipe distance between the thermometer and the throttle should meet the following requirements.
A. When the diameter of the thermometer casing is less than or equal to 0.03 times the inner diameter of the process pipe, it is not less than 5 (or 3) times the inner diameter of the process pipe.
B. When the diameter of the thermowell is between 0.03 and 0.13 times the inner diameter of the process pipe, not less than 20 (or 10) times the inner diameter of the process pipe.
3. When installing the thermometer on the downstream side of the throttle, the distance between the thermometer and the straight pipe should not be less than 5 times the inner diameter of the process pipe.
* When measuring the steam flow, the upper half of the process pipe is within an angle of 0 to 45 degrees from the horizontal centerline of the process pipe.

4. When the orifice plate is flanged, the following rules should be met:
a. The axis of the upper and lower sides of the pressure-receiving hole should be equal to 25.4±0.8 mm.
b. The diameter of the pressure tapping hole should be between 6 and 12 mm, and the diameter of the pressure tapping hole on the upstream and downstream sides should be equal.
c. The axis of the pressure tap should be perpendicular to the axis of the process pipe.
5. When using the pressure equalizing ring to take pressure, the pressure tapping holes should be evenly arranged on the same section, and the number of pressure tapping holes on the upper and lower sides must be equal.
6. Measure the amount of vapor to set the air conditioner. The installation elevation of the two condensers must be the same.

d), the source source component
1. The installation position of the source source component should be selected where the level change is sensitive and the detection component is not subjected to material impact.
2. Installation of the compensating balance container. When the balance container is fixed, measures should be taken to prevent damage due to thermal expansion of the process equipment.
3. Install the length of the connecting pipe between the flange for the float level alarm and the process equipment, and ensure that the float can move freely within the full range.

e) ,Analysis of source components
1. Analyze the installation position of the source component, and select the place where the pressure is stable, sensitive to reflect the real component, and representative of the analyzed medium.
2. When the gas to be analyzed contains solid or liquid impurities, the elevation angle between the axis of the source component and the horizontal line should be greater than 15 degrees.