Questions about socket welding
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As shown in the figure below, socket welding should involve inserting the steel pipe into the socket hole; in other words, the outer diameter of the steel pipe should be smaller than the diameter of the socket hole? However, according to the self-control installation manual, the connection between components V and 1 is Φ22, while the connection between components 2 and 3 is Φ18. It makes sense if it’s butt welding; is it okay to write it as socket welding?
Yes, socket welding involves inserting a steel pipe into a socket to achieve connection; therefore, the outer diameter of the steel pipe should be smaller than the diameter of the socket, so as to ensure the sealing and stability of the joint. At the same time, when performing socket welding, it is also necessary to pre-treat the joint, such as by cleaning and derusting, to ensure welding quality. .
No problem. Because both ends of component 2 can be inserted into a Φ18 pipe. The Φ18 end of Component 1 is inserted into the tube and welded to Component 2.
Well, the interface for Component 2 is specified as φ18, but it should actually be larger than φ18; otherwise, the steel pipe won’t be able to be inserted
Plug welding is used for the matching of pipelines of this specification, not the actual outer diameter of such fittings. Plug-welded pipe fittings are all specified by their inner diameter.
1. Isn’t it just a change in diameter – from Φ22 to Φ18? What I’m trying to say is that nowadays, except for those made by Yokogawa, most pressure transmitters no longer use this type of connection; does that mean the installation diagrams need to be redrawn? Generally, only those with low pressure use this form (of precision).
If diameter change isn’t required, should a blind flange be used? I usually buy Parker’s threaded ball valve + threaded adapter fitting + instrument pressure lead tube
From the provided drawings, we cannot see the manufacturing standards for the fittings and pipes; only the outer diameter is given. Metric data is hard to find; we found a dimensional chart for British standard socket-welded pipe fittings. Taking the British standard seamless steel pipe closest to 22 inches as an example, the standard outer diameter of a 4-inch pipe is 21.3. As can be seen from the diagram, the inner diameter range of the corresponding standard socket-welded pipe fittings for 4-inch pipes is between 21.8 and 22.2, meaning that the radial gap between the socket and the pipe is between 0.5 and 0.9.
Part V is a welded valve, with a pre-installed inner hole diameter of 22 mm. Part 1 is a terminal connector with a tapered shape, having an outer diameter of 22 mm at one end and 18 mm at the other; part 2 has an outer diameter of 18 mm. The 22mm outer diameter portion of Part V and Part 1 is joined by socket welding, while the 18mm outer diameter portion of Part 1 and Part 2 are joined by butt welding. Go and consult your construction plumbers and welders; they all know how to carry out the work.
Go and see it in person and everything will become clear:$
Just take a look at the actual construction and everything will become clear