Issue with the temperature gauge insertion depth in the pipeline?
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For pipelines with a diameter greater than 80 mm, what are the requirements regarding the insertion depth of the insert-type thermometer? Could you give some specific examples!
What is a medium? Thermocouple or thermal resistor? For thermocouples, 5-10D is about right; as for thermal resistors, they can be placed at the center of the pipe.
It is advisable to place the temperature measurement point at the center of the pipeline!
HG/T 20507-2014 Specifications for the Selection and Design of Automation Instruments 4.1.2 The immersion depth of the temperature sensing element shall meet the following requirements: 1 The selection of the immersion depth for the temperature sensing element should be based on the principle of inserting it into a region of the medium being measured where temperature changes are sensitive and representative. 2 When the temperature sensing element is installed vertically on a fully filled fluid pipeline or at 45° to the pipe wall. When the sensor is installed at a corner, the length of the end of the temperature sensing element that is submerged into the inner wall of the pipe should be no less than 50 mm, and no more than 125 mm. 3 When installing the temperature sensing element in the equipment, the length of the end of the temperature sensing element that is submerged within the inner wall of the equipment should be no less than 150 mm. When installing on flue ducts, furnace chambers, and equipment with insulated material cladding, the appropriate type should be selected based on actual requirements. SH/T 3104-2000 contains information regarding the insertion depth; for some reason, the 2013 version only includes this qualitative description
I calculate the insertion depth as follows: diameter divided by two + wall thickness + height of the mounting base
It’s actually not that complicated. Put simply, avoid installing pipes in awkward, curved positions, and also avoid locations with a large area of erosion (i.e., avoid curved pipes). Whether they are horizontal or vertical pipes, just install them such that their insertion depth is at the middle of the pipe; this applies whether it’s steam or liquid. Try to install it facing the direction. Whether it is a thermal resistor or a thermocouple
HG_T20507-2014 specifies principles in the Regulations for the Selection and Design of Automated Instruments:
Installed at the center of the pipe in the straight section
If the flow rate and erosion are high, when installed on equipment or large-diameter pipelines, the insertion depth can be slightly reduced.