Metrication & designation voor piping community?

[Piline]

Dear members,

As a piping design engineer I am quite familiar with EN, ASME and MSS standards. By regularly checking this site you will see how technical issues are compared with the rules of the Codes and Standards. I know the comments of many MPVs (member of the Eng-Tips forums round table), but what does MPV mean?

STD, XS & XXS come from the IPS system and the schedules appear in the NPS system. Also in the ASME B36.10M, STD, XS & XXS are in the Identification column and not the schedule column, which is why I do not give it the abbreviation SCH. So SCH XS becomes XS.

I got the following descriptions from this forum. The second rule is according to the metrication and then the emphasis is on the nominal designation. The most important items are named and placed chronologically.

1--PIPE, 1.5” OD X 0.109” WT, SMLS, SCH XS, ASME B36.10, ASTM A106-B, Ends beveled 30º
2--PIPE SMLS, BE, NPS 1 1/2, XS, ASTM A106-B, ASME B36.10M

1--ELBOW, 12.75” OD, 90º LR, WE, 0.688” WT, ASME B16.9, CS ASTM A-234 WPB
2--ELBOW 90º LR, BW, NPS 12, SCH 80, ASTM A-234 WPB, ASME B16.9

1--REDUCER, 12.75” OD X 8.625” OD, WE, 0.688” WT, 8” X 0.500” WT, ASME B16.9, CS ASTM A-234 WPB
2--REDUCER CONC, BW, NPS 12 x 8, SCH 80 x SCH 80, ASTM A-234 WPB, ASME B16.9

1--FLANGE 8.625” OD X 0.375” WT, RFWN, ASTM A-105 B
2--FLANGE WN, RF, NPS 8, 0.375” WT, ASTM A-105 B, ASME B16.5
or
2--FLANGE WN, RF, NPS 8, CL 150, BORE 7.875”, ASTM A-105 B, ASME B16.5

The following descriptions come from a 3D CAD design catalog;
PIPE SMLS, BE, 100mm ND, SCH 120, ASTM A106
REDUCER CONC, BW, 65mmX40mm ND, ASME B16.9

They do not meet the objective of metrication. The design engineers then have to choose from;
2 1/2 x 1 1/2 REDUCER CONC, BW, 65mmX40mm ND, ASME B16.9

But according to B16.9 this should be;
2 1/2 x 1 1/2 REDUCER CONC, BW, DN 65 X 40, ASME B16.9

The size 2 1/2 x 1 1/2 is the NPS notation and the description is linked to it. This will be included in the MTO. So there are two unit systems together.
According ASME B16.9 para. 1.4-relevant units; Combining values from the two systems constites nonconformance with the standard. The designation for the size is NPS for both Metric- and Customary-dimensioned fittings

I would rather see;
2 1/2 x 1 1/2 REDUCER CONC, BW, NPS 2 1/2 x 1 1/2, ASME B16.9

BE–Beveled end, BW–Butt weld, PE–Plain end, WE–Weld end
How should you handle butt joints and what additional information does this abbreviation provide? Or does the type of welding method also play a role? In most cases I see that PE or BE is used for pipe and BW for fittings. You can use Plain end (PE) for socket weld and the weld ends are still pre-processed in the pipe shop. Do these abbreviations provide extra usefull information?

For this post I read a lot about metrication and I think it is a good point for calculations in the SI system. Metrification is not mandatory, monetary costs, conversiefactor inch & mm, world of piping design is conservative. So, in my view, economics and the conversion factor are the problem.
Why do you have to put such a large (piping) system of the U.S. Customary system, which is also well known in Europe, in a metric form? I don't think it has become any clearer and that is why I am asking the MPVs for a second opinion.

1-How is metrication (excluding calculations) experienced among piping engineers?
(i.e. how is the expression or name perceived)

2-Why are ASME dimensional standards often not included in the description?

3-Do the abbreviations BW, BE, etc. provide additional useful information and if so, how to classify?

Regards,
Piline

 

[LittleInch]

1) It's MVP and stands for Most Valued Poster, or something like that.... MPV is a Multi Purpose Vehicle, which also kind of matches as well, but isn't used in this case.

If it's XS or STD then forget about adding SCH in front of it.

I'm not quite sure what your post is asking, but lets go with the questions at the end.

1) Varies depending on customer , location and what that design or operating company prefer. Mostly I see inch NPS used, but metric NPS is becoming more common as time goes on.

2)Basically because everyone uses them so there is no need to keep stating it for no purpose. I don't know of any other standard giving this data so no need to take up space. If you're quoting fittings to any ASME standard then the sizes will comply with that standard (B36.10M)

3) BE and PE usually refer to pipe IME or fittings sometimes, but PE is rare in fittings. BW is usually for fittings or flanges where other options exist, e.g. Socket Weld (SW), Slip on (SO) etc. WE is usually for valves where you can have flanges or a Butt Weld or sometimes both ont he same valve, so you get FE/WE where you weld one side of a valve, but have flanges on the other side #9usually the first valve off a pipeline is FE/WE.





Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[GBTorpenhow]

I'll add:
1) Personally, in the US O&G industry I have seen metric references in a piping BOM context exactly zero times. I wouldn't expect that to change as inches, pounds, gallons, Btu, scf, etc. are dug in pretty hard.
2) The ASTM material standards often reference ASME dimensional standards, so there is no need to to reference them separately and they can be left out for the sake of brevity. For example ASTM A234's first clause is: "This specification covers wrought carbon steel and alloy steel fittings of seamless and welded construction covered by the latest revision of ASME B16.9, B16.11, MSS-SP-79, MSS-SP-83, MSS-SP-95, and MSS-SP-97." Specifying A234 for a BW elbow means you get a B16.9 elbow by default.
3) Usually end connections are needed, but not always. If I am listing cut lengths for spool fabrication, then the BE, PE or threaded end info is important. Likewise for nipples and swages. If I am buying pipe in double randoms to chop up for fabrication I don't really care about showing BE or PE. If the end connection is already given or implied, I don't need it, like a WNRF description doesn't need to say "BW".

 

[KevinNZ]

Imperial pipe sizes are NPS eg 50"NPS, metric is DN e.g 50NPS is DN1250. Do not use NPS with metric sizes e.g if ask for 50NPS you will get 50" pipe.

Our projects are outside of the US and we have moved to almost all DN sizing. But well drilling are a complete hold out. eg. 13 3/8" casing.

 

[XL83NL]

Hi there,

below some suggestions from my experience. I think its all just a matter of where you live, and what your local or national is like (Im Dutch, so our MTO has a different call-out than e.g. a US or Canadian company);

1--PIPE, [highlight #EF2929]NPS[/highlight] 1.5” OD X 0.109” WT, SMLS, SCH XS, ASME B36.10, ASTM A106-B, Ends beveled 30º
2--PIPE SMLS, BE, NPS 1 1/2, XS, ASTM A106-B, ASME B36.10M

1--ELBOW, 12.75” OD, 90º LR, WE, 0.688” WT, ASME B16.9, CS ASTM A-234 WPB
2--ELBOW 90º LR, BW, NPS 12, SCH 80, ASTM A-234 WPB, ASME B16.9

1--REDUCER, 12.75” OD X 8.625” OD, WE, 0.688” WT, 8” X 0.500” WT, ASME B16.9, CS ASTM A-234 WPB
2--REDUCER CONC, BW, NPS 12 x 8, SCH 80 x SCH 80, ASTM A-234 WPB, ASME B16.9

1--FLANGE 8.625” OD X 0.375” WT, RFWN, ASTM A-105 B (A105-B isn't a grade, but option 2 is better)
2--FLANGE WN, RF, NPS 8, 0.375” WT, ASTM A-105 B, ASME B16.5 (I would not call out 0.375" wt but just the schedule and either B36.10 or .19)
or
2--FLANGE WN, RF, NPS 8, CL 150, BORE 7.875”, ASTM A-105 B, ASME B16.5

for an isometric, I don't call out the ends of the fitting or pipe. the WPS shall determine that, whereas we (as the contractor) will specify whether a system is either butt or socket welded.

Above 12", always callout either B36.10 or .19, as Sch40S or Sch40 are different and some folks don't know. for such cases, adding the nominal wall thickness could be useful.

Huub
- You never get what you expect, you only get what you inspect.

 

[Piline]

Hello,

A small addition to my original post from yesterday. What perhaps my handicap is that I am from overseas (retired, Dutch) and there we work more with EN standards, while in this post I only want to talk about the ASME/ASTM in combination with metrication. Perhaps an other problem, I am not a material engineer.

A fair comment from LittleInch. I got the first 'view' with rules no.1 from this forum and they are from after 2019, so they are fairly recent. The 2nd line is my interpretation of how the metrication is applied, you can comment there but it is not necessary, I gave some examples.
Below of it there are 3 designations from a 3D CAD catalogue, this is a database provided by an Australian company for 3D piping software and provided with many mistakes. Before I comment, I needed a second opinion from this forum about metrication.

I might draw the notation “ASME B16.9 para. 1.4-relevant units; Combining values ​​from the two systems constitutes nonconformance with the standard. The designation for the size is NPS for both Metric- and Customary-dimensional fittings”. out of context and that it is intended more for calculations.

How should I read the underlined phrase….NPS for both Metric- and Customary..??

NPS is expressed in; NPS 1/2 – NPS 1 – NPS 1 1/2 – NPS 2 etc.
DN is expressed in; DN 15 – DN 25 – DN 40 – DN 50 etc.

You can't combine these two expressions under NPS, or am I totally wrong?

I hope my original post has become a bit clearer now and if anyone knows an answer to “ASME B16.9 para. 1.4-relevant units”, then we would like to know, because ASME is actually letting me down.

Thanks,
Piline

 

[LittleInch]

What ASME B 16.9 in section 1.4 says is that the designation for sizes is NPS, i.e. inches for both the tables where the dimensions are in metric (the main tables) and for those where the dimensions are in inches (Mandatory Appendix I).

so e.g. you look in table 1 for the dimensions of an elbow all the sizes are listed in NPS (4,5,6,8 10 inches), but all the dimensions are in mm.
Table I-1, all the sizes are in NPs inches, with the dimensions also in inches.

ASME does NOT, AFAIK, use the metric DN or NB sizes anywhere except ASME B 36.10M

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.