Selection of materials for chemical process pipelines

Carbon steel painted or 304, depending on your requirements for cleanliness

The choice of material is determined based on the corrosive nature of the fluid; factors such as pressure and temperature are also taken into consideration. If it’s just hydrogen or nitrogen, SS304 is sufficient, and there’s no need to pursue higher quality materials. As for carbon steel pipes, they are not highly recommended, as iron particles can still cause contamination over time due to prolonged use. The above information is provided for reference only

One more question: once the DN and PN are determined, is the wall thickness of the pipe also determined? If it’s determined, which standard should be referred to? Can 20# steel be used for circulating water transmission? Or which material is better.

DN has been determined (I don’t know what PN is); basically, the wall thickness is set, unless you want to thicken it in which case there are different grades. For standard cases, there are relevant tables available for reference. Circulating water systems use 20# steel; according to online information, this is a low-carbon steel, and ordinary carbon steel pipes should suffice

I just graduated this year and am a newcomer at the design institute; after three months here, I was assigned to design an air compressor station, and I was completely lost. The owner didn’t provide all the necessary information; the company gave me those original drawings and asked me to work based on them, but many things were different. There’s no training when I start working at the company, and the managers don’t come to provide guidance since they usually have nothing to do. They just answer questions without teaching any methods, focusing only on pushing for progress. There are no other newcomers in the company either, and there are few activities held; I’m almost developing depression, and I’m thinking about resigning by the end of the year. Getting started with design is too difficult – there are things like process flows, layout planning, piping, and so on. Maybe I’m not smart enough; I didn’t even come across this stuff in my university courses in environmental engineering. Now I don’t even know if there are any issues with the processes involved. As for various valves and instruments, I have no idea where valves or instruments need to be installed, whether they should be integrated into a DCS system, which ones should be controlled pneumatically or electrically. I also don’t know how to choose the right pipe materials, nor do I know if it’s possible to fit the pipes according to the layout plans provided. I was also worried that it might explode, and then I’d end up in jail. The supervisor often goes on business trips. If I’m first asked to assist with a project, it would be great if I could take on several more projects and eventually be in charge of one entirely on my own. The company atmosphere is terrible, and I really can’t stand the way new employees are trained. I don’t know what the future holds. The girl I like is going back to the Northeast before the New Year, and there’s nothing that can keep her here; I’m afraid I won’t be able to take good care of her. At such a good age, Alexander feels no hope and even becomes disheartened.

I’m also a newcomer; I’ve only been at the design institute for less than a month. I don’t have any special training either; at first I was assigned to relatively simple tasks such as those related to gas pipeline supply systems. However, there are many experienced colleagues in our process team, and whenever I encounter something I don’t know how to handle, I turn to them for help. However, many times it’s just giving fish without teaching how to fish; it would be good if there were some systematic training available. Before coming here, the manager also said that it’s impossible to take on responsibilities on one’s own without at least five years of experience; we’ll just observe and proceed step by step.

You’re no longer in school; you’re working now. In a design firm, there’s at least proofreading and review, and someone will be assigned as your mentor. At first, you might not know how to do things, but since you’re no longer in school with teachers to guide you, you have to rely on yourself. You’ve written so many \"shoulds\" and \"shouldn’ts\" – ask your mentor, the proofreaders, other colleagues, and those who work in instrumentation about these issues, so that what you don’t know can be turned into knowledge. With time and consistent effort, it will work out. Working as an assistant for others doesn’t allow you to get started on projects as quickly as working on your own projects; however, you need to ask more questions, as no one will teach you things on their own