I have a question regarding the length of the nozzle
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Today, while filling out the table for the connection methods and specifications of the instrumentation equipment, there was a column for nozzle length. When filling in the information for bimetallic thermometers, I hadn’t paid much attention to this field before; I simply entered 200 mm as suggested by others. I took a look today at the nozzle lengths filled in by others, and found that there are three specifications: 100mm, 140mm, and 170mm; the corresponding pipe lengths are 80, 150, 200, and 450. I was just wondering if there are any rules or considerations regarding the determination of this nozzle length?
In accordance with the requirements of the \"Installation Atlas for Automated Instruments HG/T21581-2012\", the length of straight connectors is mainly set at H=120 and H=140; in fact, too long a length is not desirable. These two values are sufficient to meet the requirements for different pipe diameters.
I checked the specifications, and it indeed states that straight connectors of types 120 and 140 are required. By the way, may I ask about your last sentence: “Using these two methods can both meet the requirements for different pipe diameters.” ”Do different pipe diameters impose different requirements on nozzles? Newcomers don’t understand much.
I also found on the Internet that there is a standard called 70TJ001, which is said to be a **standard for instrument nozzles**, but it couldn’t be downloaded.
The last edit to this post was made by hxch150804 on 2021-12-27 at 12:06. Regarding the requirements for thermometer measurements, the sensor part of the thermometer must be located at the center of the pipe; in other words, the insertion depth of the thermometer equals the length of the straight connector plus half of the pipe diameter
You can refer to this diagram, but it is not a strict requirement; what’s most important is to consider the thickness of the external insulation and its depth of insertion.