NPT and ANSI to Metric transition

[rb249]

I am currently involved in a project wherein US made components such as Pipe thread and ANSI flanges will need to be mated up to the Metric(DN) standard pipe and flanges in Europe (specifically Spain). I am looking for information which will let me steer contractors to the right parts, components and products to make the connections. If someone could explain to me or send me info which will enable us to accomplish the above I would greatly appreciate it. Thanks in advance.

 

[MikeHalloran]

Call your Swagelok supplier and get a catalog. They stock a huge array of connectors between NPT | BSPT | BSPP | whatever.
That will take care of the threaded connections.






Mike Halloran
Pembroke Pines, FL, USA

 

[rb249]

Thanks Mike, I will check that source also. The problem I am encountering is such. After checking various vendor charts, I see discrepancies in the flange bolt circles, "mm" identification/conversion, pipe OD/ID, etc. between them. I am also being told that the only difference between our NPT and the europe ISO metric is that we use a nominal inside diam for NPT and they imply a nominal outside diameter for basically the same pipe and thread. I know that the groove pitch for NPT and Metric is 60 deg., but I am not so sure on taper/thrd per in. I understand that the BSP(P or T) is different than the NPT but also the ISO(DN). I gues the questions should be posed as such to the experienced "world traveler" of piping. If I send a 3" ANSI (80mm) flange to Spain, will the Spanish supplied threaded pipe of DN thread right into it without issue, or is an adaptor of some fashion required? I suppose that's the simple of it. Same with a 1" NPT male thread, will a 32mm DN fitting mount right to it? Or do I really need an adaptor? I will appreciate any vendor info and charts sent, but basically the above is my simple dilemma. I have 25 years experience fitting up many ANSI, ASTM, NPT, API etc. within the US for Water Utility, Steam Plants and Industrial Piping sytems. I have never done a european job where US made parts must be fitted to european pipe.

 

[MikeHalloran]

For threaded connections, some combinations will >sort_of< fit, will leak, so _somebody_ has to supply an adapter. Who does that is basically a contractual issue. Somebody at some point _should_have_ defined exactly what connections or pipes cross the lines of contractual demarcation. Maybe nobody got around to it; maybe it's on the P&ID; maybe it's in some boilerplate.

For flanged connections, somebody probably has to make a spool piece. The simplest tactic, IMHO, is to supply a usable blind flange instead of a thin shipping cover. That also _should_be_ documented somewhere...



Mike Halloran
Pembroke Pines, FL, USA

 

[micalbrch]

We have pretty often the same problem, just in the other direction (Europe - USA). As far as I know there are no standard connectors (catalogue goods). We manufacture our flange and threaded adapters by ourselves. It is not a big deal and this stuff is not that expensive. The thread standards you need are DIN 259 (ISO 228) and DIN 2999 (ISO 7/1). You can find the dimensions everywhere in the internet. Both threads are common in Spain.

It is basically the same with flanges although I know that spool pieces for welding neck flanges can sometimes be manufactured just be welding the two flanges together. There are various DIN and ANSI flanges which have the same pipe OD. This must not be done for pressure vessels but for non-pressurized connections this is common practice.

 

[BigInch]

As I recall, fitting most sizes are not a problem except for 2" and below, where bolt hole clearances are a bit lower than normal, but I don't remember if they will still fit up directly without some "modification", or not.

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