Connection issues with stainless steel air supply pipes
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1. For stainless steel air supply pipes of 1" and 1/2", should welding or threading be used for connection during on-site installation? Which construction method is more convenient? Can 2.1\" stainless steel pipes (outer diameter 33.4, wall thickness 3.4) and 1/2\" stainless steel pipes (outer diameter 21.35, wall thickness 2.75) have threads turned on them using a lathe? Can threading be done at the construction site using a threading machine?
Galvanized pipes are connected using threaded couplings, while stainless steel pipes or copper pipes are connected with compression fittings; seamless steel pipes can be joined by welding.
If it is to be used as an air supply pipe, welding is not recommended; one reason is that the slag inside the pipe is difficult to deal with, and it may damage the equipment； It’s very inconvenient for the instrument operators when they need to carry out tasks ；
If it is to be used as an air supply pipe, welding is not recommended; one reason is that the slag inside the pipe is difficult to deal with, and it may damage the equipment； It’s very inconvenient for the instrument operators when they need to carry out tasks ；
For stainless steel, threaded connections are generally not used! Multiple for socket welding
In this case, flange connections should be used. Easy to repair.
Stainless steel pipes with a diameter of 1 inch and 1/2 inch are generally welded, using TIG welding to prevent slag from entering the pipe. For stainless steel pipes with a diameter of less than 10 mm, compression fittings should be used for connection. Galvanized pipes are generally not allowed to be welded; threaded connections should be used instead.
Flange connection is still better for this
Welding is more reliable. We are all welders. It is rarely serviced. Of course, it needs to be welded by professionals
Most of the main air supply pipes are welded on-site, which reduces air leaks. There is an air supply ball valve between the 1/2\" pipe and either the main air supply pipe or the branch air supply pipe, and these are usually connected using collets.
Argon arc welding is recommended for the main stainless steel gas supply pipe to reduce leakage points. It is recommended to use a bayonet connection for the air distribution pipe.
Stainless steel gas supply pipes are generally welded using TIG welding; argon or nitrogen is filled inside the pipe during welding to prevent oxidation and slag formation. It is advisable to use threaded valves or flange valves at the ends of the branch pipes for easy maintenance in the future
Galvanized pipes are connected using threaded couplings, while stainless steel pipes or copper pipes are connected with compression fittings; seamless steel pipes can be joined by welding. This method is adopted by many organizations.
The ferrule connection works well; the air supply pipe is usually a thin-walled steel pipe, and welding it properly is difficult to control, and it’s also hard to clean the pipeline during purging
For sizes under 1/2", a ferrule connection is preferable, while argon arc welding can be used for 1".
The gas source should be very clean. Once stainless steel pipes are installed, they are virtually maintenance-free. Of course, proper welding is essential; flange connections and threaded connections can have leakage points, while socket welding prevents weld slag from entering the pipes.
Since both 4-inch pipes and 1-inch pipes are relatively thick gas supply pipes, I don’t think using collet connections is very convenient; instead, TIG welding is more suitable – just my personal opinion
1. For stainless steel air supply pipes of 1" and 1/2", should welding or threading be used for connection during on-site installation? Which construction method is more convenient? Either is fine; threads are convenient, but high quality is required for the materials and construction. Can 2.1\" stainless steel pipes (outer diameter 33.4, wall thickness 3.4) and 1/2\" stainless steel pipes (outer diameter 21.35, wall thickness 2.75) have threads turned on them using a lathe? Can threading be done at the construction site using a threading machine? Sure. It’s difficult to work on site because it’s too hard. Since the threading machine can’t be used, I’ll just work on carbon steel pipes.
Connections of 1/2\" and below shall use ferrule connections. For sizes larger than 1/2", flange connection is the simplest and most reliable method. Threaded connections are inconvenient to disassemble and prone to leakage. Welding is not easy to maintain.
1. For stainless steel air supply pipes of 1" and 1/2", should welding or threading be used for connection during on-site installation? Which construction method is more convenient? Of course, it needs to be well-welded and easy to construct. Can 2.1\" stainless steel pipes (outer diameter 33.4, wall thickness 3.4) and 1/2\" stainless steel pipes (outer diameter 21.35, wall thickness 2.75) have threads turned on them using a lathe? Is it possible to thread parts using a threading machine at the construction site? If threading is necessary, it is better to fabricate threaded sections on a machine tool and then weld them in place, as stainless steel is too hard, making it difficult to use a threading machine.
First, to answer the second question: it is not possible to thread stainless steel pipes on site, as this does not meet the required standards. As for the first question, it is generally solved by welding a threaded fitting to the stainless steel pipe, and then using an internal threaded ball valve to connect it to a pipe with a φ8 socket