Are flanges divided into large outer diameter and small outer diameter?
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Recently, our company needs to install a DN150 pipe; the diameter of the pipe itself is 168. Valves and flanges need to be installed at intervals along the pipe. Are there two different outer diameters for these valves and flanges – 159 and 168? Do we need to specify explicitly when purchasing them that the pipe to which they will be welded has a diameter of 168?
These are pipes from series A; you need to mention it when purchasing flanges, but the valves are not an issue
It’s related to pipes. The valve diameters are all the same
Two systems: one in Europe and one in the Americas
Don’t flanged valves also come with flanges? If they are flanged, shouldn’t there be two types of them? Otherwise, how can they be matched?
Flanges in HG/T 20592-2009 are divided into Series A and B, corresponding to Series I and II of pipes specified in HG/T20553-2011. For flanges of Series A, no special indication is required, as they are assumed to be of Series A by default.
Either you check the pipeline grade table, or you standardize it
The 168 tube refers to the outer diameter; it belongs to the A series, and a flange with an inner diameter of 170.5 mm will suffice.
The flange size parameters for A/B series pipes are the same; the only difference is the inner diameter of the flange. Flanged valves are connected by flanges to other flanges, not to pipes; therefore, the valve is not affected
Today, there are very strict requirements for pressure pipelines; it’s better to have a design firm prepare the drawings, as this will provide a material list as well, which makes it easier to undergo inspections in the future. Otherwise, if any problems arise or if an inspection is conducted on such a pipeline, it will be difficult to handle the situation. It’s safer to go with a process change, unless you’re the boss and costs aren’t a concern.