I haven’t been here in three years! Coming right away with a question! Regarding jacketed butterfly valves! Details
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I work on butterfly valve design! Today, the manager gave a requirement: a DN1200 butterfly valve for the steam jacket. Steam pressure: 2.0 MPa. I was completely confused as soon as I heard it; it was the first time I had come across steam with such high pressure. After searching through various sources, for DN1200, PN40, there are no standards whatsoever regarding flange dimensions or pipe wall thickness. Please advise: 1. Could it be that the steam pressure value was provided incorrectly by the customer? 2. If it is correct, then it is a pressure vessel with PN20 pressure between the jacket and the valve body. How to choose a flange, and how to calculate the wall thickness of the jacket and valve body (for welded butterfly valves)?
There is a statement from page 612 of the maintenance manual for petrochemical plant equipment, titled \"Process Piping\": The use of jacketed tubes for heating requires a large amount of steel, and the construction work involved is also extensive. In refineries, besides the use of steam jacketed heating for pipelines carrying media such as asphalt, paraffin, and sulfur, it is rarely used elsewhere. What I mean here is: among the three media mentioned above, sulfur has the highest freezing point, at 119–121 degrees, and the heating steam pressure for sulfur jacket tubes is usually 0.3–0.4 MPa. The poster should check where this valve is used
A chemical product! Insulation is needed! This seems to have nothing to do with the topic!
What he means is that for 2.0 Mpa, the steam temperature should be 215 degrees; is such a high temperature necessary for heat tracing?
This jacket is likely the jacket of a heat-containing container, and this butterfly valve is used to supply air to this jacket. This has nothing to do with heat tracing. What is being examined are the piping issues related to such high-pressure steam pipes
For butterfly valves equipped with jackets, it is possible to ask professional butterfly valve manufacturers whether they can design ones for such large diameters; in theory, jackets can indeed be installed； Also, is the DN1200 pipeline matching it also made as a jacketed type? If the pipeline is heated using electric tracing or steam tracing, it is sufficient to wrap a few turns around the valve; however, care should be taken to ensure that the design does not hinder the valve’s disassembly, assembly, and operation.
Let me restate my question: What is the temperature of steam at 1.2 MPa? Saturated and superheated! The customer also didn’t specify which one! 2. For DN1200, PN20, how should the wall thickness of the jacket and the valve body be calculated? Because **there’s no standard either!
The first question must require the customer to clarify; it’s not you who decides； For the second question, refer to the following: 1. The 2014 version of the \"Guide to the Selection of Industrial Valves\" provides specific information on jacketed valves, but this information is limited to aspects such as structure, testing, and manufacturing requirements; there is no calculation for the thickness of the jacket wall ； 2. Section 7 of Chapter 2 of the 2014 edition of the \"Guide to the Selection of Industrial Valves\" details the regulations for calculating valve wall thickness, describes various scenarios separately, and lists the corresponding standards ； \"Practical Questions and Answers on Valve Technology (Second Edition)\\", published by Standard Press in 2008; questions 2–5 describe the calculation of valve body wall thickness in terms of thick-walled and thin-walled vessels, on a qualitative basis. That is, there are regulations regarding the calculation of the valve body wall thickness ； 3. We reviewed the documentation related to the imported jacketed valves for our project; there are requirements regarding manufacturing tests and pressure specifications, with the pressure in our heating medium system being lower than the internal pressure of the valves, but no basis for the calculations was provided ； 4. Personal opinion: The wall thickness of the jacket is closely related to the pressure of the heating medium, which in turn depends on the heat sources available or accessible at the site. Based on experience, choosing a steel plate with a thickness that is commonly used is sufficient to ensure successful passage of pressure tests. Careful manufacturing and processing are required; otherwise, the appearance will be poor and stress will be applied to the valve.
Could you provide a copy of the 2014 version of the \"Guide to the Selection of Industrial Valves\"? 603293474@qq.com Thank you
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