Are all thermometer sleeves nowadays made of integrally drilled sleeves?

As I understand it, overall drilling is used when there is a lot of pressure; if money isn’t a concern, then overall drilling can be used as well: lol

The supplier makes the judgment based on the requirements provided by the design institute: D

The integral design ensures greater stability in the stress distribution of the sleeve, but the manufacturing cost is necessarily higher (the processing is more difficult compared to assembly, due to the requirements related to the temperature sensing elements and the insertion depth). Currently, there are those that are made as a single unit, as well as those that are formed by welding two pieces together. Laser welded ones can also meet the requirements for strength and service life. Currently, the professional approach is to carry out relevant calculations in accordance with ASME PTC19.3. Then the design drawings are used for processing. For technical consultations, you can add me on WeChat; let’s learn together!*

In situations with high flow rates, deep penetration, and high pressure, it is necessary to consider using a complete set of drilling sleeves for protection； For other applications with low pressure and low flow rates, pipe sleeves can be used. Of course, what we’re talking about here is quite general; to determine what constitutes a high flow rate, what means a long insertion depth, and what represents high pressure, technical knowledge is required. The American standard ASME PTC19.3-2016 is now at its 2016 version. We have software to do the calculations. The basic parameters must be provided: medium temperature, pressure, flow rate, density, and even viscosity. Additionally, information on the depth of insertion of the sleeve, its dimensions, and its material is required. As for whether to use a rod-shaped sleeve or a sleeve made by welding pipes, this should be determined by the design institute or engineering company ； Then the thermometer supplier is simply responsible for producing them as required. However, China is in a phase of rapid development, experiencing changes on a scale not seen in a century. With design institutes and engineering companies so busy, how could they possibly worry about whether it’s the drilling of the entire sleeve or the welding of the pipes? They simply leave everything to the suppliers. The supplier is willing to do it or not; anyway, someone will do it. Forcing everyone to learn *new skills. Next, the design institute discards this aspect, and as a result it no longer has any distinction between the details related to overall drilling and pipe welding; the specification sheet treats the overall drilling sleeve as the standard, since there’s no error in that. . As for suppliers, those who are not very smart, or who are stubborn or overly cautious, will charge a price based on full drilling; of course, their chances of getting the order are relatively low ； Those who can think quickly and communicate well with the client, or who act decisively, can simply quote the price for welding the pipes, receive the order, and deliver the goods – with possibly no one to oversee the process. That's all about it

This post was last edited by Guangzhou Uprising on 2022-5-17 at 14:49. I think it should be determined by the flow rate and the corrosiveness of the medium.

This post was last edited by feng*aosa on 2022-5-17 16:10. Do not take things out of context. Except for hydrogen-handling units or those with a design pressure of 6 MPa or higher, it is generally not necessary to consider an integral drilled tapered casing. Additionally: the protective tubes mentioned by instrument manufacturers are often confused with the protective sleeves specified in the design. The casing, protective tube, and protective sleeve of a temperature instrument are three distinct components, but these terms are often used interchangeably by people from different fields. .

Definitely choose the overall hole transformation option; there’s no need to consider anything else

There are very few products on the market that come with fully drilled holes by default; I’ve seen some people claim that even 4-meter-long protective sleeves have fully drilled holes. The person in charge of temperature control at a Fortune 500 company went to domestic manufacturers; instead of focusing on how the sensors are made, he headed straight to the machining workshops to find gun drills and saw how long they could drill – what a savvy person! That’s why only capitalist societies know where their core competitiveness lies; we follow behind, working hard yet earning no money.

I forgot to reply to the original poster – it is the design institute that makes the decision, as from a financial perspective, the design institute is responsible for the overall design and receives fees for that work. The suppliers are only responsible for delivering the goods; more reliable suppliers will use the ASME PTC 19.3 standard to carry out the calculations. However, the design institute may not provide enough parameters for accurate calculations. The key issue is that all these details come from the design institute, as the suppliers don’t receive any fees for their work.

If a 4-meter-long piece is to be drilled entirely, the machine tools and drills used wouldn’t be ordinary ones; the cost must be extremely high – it’s enough to make someone exaggerate