Welding process for the gasket ring between the head and the cylinder of pressure vessels
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For stainless steel storage tanks, RT testing is required for the welds, but no manholes are provided. There are generally two methods for welding the seam between the upper head and the tank body: The first method involves filling the interior of the equipment with argon gas and performing single-sided welding to achieve double-sided formation; however, this method can only be used for small storage tanks, as the amount of argon gas needed is large when the tank volume is large, resulting in high costs. The second method involves installing a stiffening ring between the top head and the shell; this is generally used for medium- to large-sized storage tanks without manholes. Question: 1. For storage tanks with a volume exceeding what amount (in liters), is the lined-ring welding process used? 2. Is the welding process for backing rings mentioned in any specification? I checked the pressure vessel specifications but couldn’t find it. 3. Are there any precautions for the gasket welding process? For example, are there any limits on work pressure and working temperature?
1. Generally speaking, storage tanks with a volume of several hundred liters or more are suitable for the liner welding process. The specific volume limits may vary depending on different **, industries, applications, and design standards. 2. The gasket welding process may not be explicitly mentioned in the design and manufacturing specifications for pressure vessels, as this technique is specific to certain types of vessels and applications. Typically, the relevant welding procedure specifications and standards may be mentioned in the technical documents specific to a particular industry. 3. The key points to consider in the gasket welding process include: a. Operating pressure and temperature: The selection of the gasket welding process must take into account the requirements regarding operating pressure and temperature, and it is necessary to ensure that the gasket material can withstand such conditions. b. Selection of gasket material: A material with good corrosion resistance must be chosen for the gasket to ensure that the medium inside the container does not erode the container walls. c. Connection method between the liner ring and the cylinder: An appropriate connection method must be selected, such as welding or bolting, to ensure a secure and reliable connection between the liner ring and the cylinder. d. Installation and protection of the gasket: During welding, attention must be paid to the accurate installation position of the gasket as well as the quality of the welding. During use, measures must also be taken to protect the liner ring from being eroded by the external environment. Note: The above answers are for reference only; the specific details must be determined based on actual design and manufacturing requirements. .
1. The liner ring does not have a fixed volume; larger ones are acceptable as well as smaller ones. 2. Refer to GB150.3-2011, Figure D.1(f). 3. According to GB150.1-2011, clause 4.5.2.2(b), no restrictions are specified regarding pressure and temperature
This post was last edited by wanlirn on 2023-8-21 at 11:33. Those using lining rings as a base layer have basically been phased out; for pipes with larger diameters, manholes must be added (in our company’s design specifications, this applies to diameters of 1200 or above)
The second-floor reply contains very unique insights!
1. The question refers to weld backing, which is welding with a backing plate. It seems you are referring to a gasket flange.
What should I pay attention to, haha
It’s not just a matter of welding; flaw detection is also a concern. Therefore, for storage tanks with a diameter of less than 1200 and a thickness of less than 10, it’s possible to do without manholes – a double-wall single-shadow design allows for flaw detection. However, for tanks with a larger diameter or a thickness greater than 10, flaw detection isn’t possible without manholes.