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Use of unlisted materials in ASME B16.5 B16.47

Use of unlisted materials in ASME B16.5 B16.47

Use of unlisted materials in ASME B16.5 B16.47

(OP)
ASTM A694 F60 is an unlisted material and therefore the use of which is not endorsed by the standard. Therefore there isn't a corresponding P-T rating available for the material.

What about the use of Incoloy 925 bolts. Incoloy 925 UNS N09925

http://www.vegasfastener.com/raw-materials.php

It has a UTS of 175 ksi and YS of 117 ksi vs 125 ksi and 105 ksi respectively for B7 grade bolts (High strength bolts).

Is the use of Incoloy bolts endorsed by ASME B16 standard?

A client spec advocates it's use from a galvanic corrosion consideration for SS flanges. Will this selection be correct from the above consideration that is not endorsed by the B16 flange standards?

RE: Use of unlisted materials in ASME B16.5 B16.47

svi, if no Code of construction applies you can do pretty much what you want.

Regards,

Mike

RE: Use of unlisted materials in ASME B16.5 B16.47

(OP)
Mike,

Can you please explain what that would mean?

RE: Use of unlisted materials in ASME B16.5 B16.47

Well, yeah, you don't state whether your class of work is to comply with a pressure vessel code, piping code, or so forth.

If, for example, you are working to ASME Sec VIII, Div 1 Boiler and Pressure Vessel Code, the answers to your questions are most likely contained within it.

On the other hand, if you are designing a widget that is not to comply with a Code of construction, you have more freedom to make your own decisions.

Regards,

Mike

RE: Use of unlisted materials in ASME B16.5 B16.47

(OP)
It is for the requirement for the compliance to ASME B16.5 Pipe Flanges. The governing code being ASME B31.3 Process piping code.

I have raised the question as it is not clear to me from the contents of the standard on the subject point.

The widget that I know of is one on the PC desktop. I am not trying to make one of them for sure.

RE: Use of unlisted materials in ASME B16.5 B16.47

You need to design the flange from first principles if the material is not a listed material. So use the provisions of ASME VIII  to design the flange.

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/

RE: Use of unlisted materials in ASME B16.5 B16.47

stanier has it right. I'm not familiar with piping codes, but presumably they will accept a flange design per ASME Sec VIII, Div 1, Appendix 2. If so, you would design it so using the diametral dimensions per the flange you need to match.

A caution: 1) Both the flange and bolting materials need to have allowables specified by the Code you are working to. Your proposed materials may or may not. If not allowed by Code case or interpretation, you will need to find alternates.

Regards,

Mike

 

RE: Use of unlisted materials in ASME B16.5 B16.47

From memory 316ss bolts are not a listed material either, according to ASME B16.5. I have had experience where the designer has had to provide calcualtions to justify 316ss bolts for a Class 150 flange. They could not so went to A4-70 bolts.

Surpriosing how many specifications refer to ASME B16.5 or16.47 and then call up materials that cannot effect the flange design to meet the operating and test criteria.

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/

RE: Use of unlisted materials in ASME B16.5 B16.47

(OP)
B8M (SS 316) Bolts is listed in B16.5 and B16.47 as intermediate and low strength bolts. Will not A4-70 bolt be again be an unlisted material by the ASME standard?

Yes a seperate flange calculation has be done when an unlisted material is to be used. It becomes all the more difficult when there isn't an allowable stress available for the unlisted material.

I wonder why is ASTM A694 forged steel is an unlisted material for B16.5, B16.47 and B31.3, whereas it is a listed material in B31.4 and B31.8. A flange P-T rating that is the same as for A105 is given in MSS SP 44. MSS and ASME standards are referenced from each other but not specifically the MSS SP 44 in B16.5.

  

RE: Use of unlisted materials in ASME B16.5 B16.47

"It becomes all the more difficult when there isn't an allowable stress available for the unlisted material."

You got that right:)

RE: Use of unlisted materials in ASME B16.5 B16.47

Apologies my memory has failed me again. It was a class of flange that required high strength bolting I was thinking of at the time.

It goes to show that engineers need access to these standards but how many companies invest in them, let alone allowing the time to engineers to study them?

You cannot rely upon manufacturers/suppliers. You cannot rely upon adopted specifications where someone in ignorance has changed the bolting material to save costs.

ASME B16.5 2003 is 234 pages long so is not a picnic understanding.

You could invest in this software to design your flange connections http://www.paulin.com/AxiPRO.aspx

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/

RE: Use of unlisted materials in ASME B16.5 B16.47

(OP)
TDW provides hot tap split tees comprising a flange welded to one half of the full encirclement reinforcement sleeve. The NPS 32 flange conforms to ASME B 16.47 for dimensions and material, except that the flange does not use a straight hub section. The weld happens to be at the tapered hub section. This is done so as to match the sleeve thickness to that of the flange hub at the joint. Will this deviation from the standard dimensions and configuration of the B16.47 flange be a non conformance that requires a flange calculation to validate the design?

RE: Use of unlisted materials in ASME B16.5 B16.47

svi, if you are referring to the 1/4" dim shown in Figs 1 & 2 (of my older standard) I do not believe they are specifically required.

See, first, Notes 8 & 9 of Tables 5 thru 15, see the notes for Figs 1 thru 7 and see also 6.4.4.

The above assumes the flange otherwise complies.

Regards,

Mike

RE: Use of unlisted materials in ASME B16.5 B16.47

(OP)
Note 8: This dimension is for the large end of hub, which may be straight or tapered.

6.4.4 Other welding end preparations furnished by
agreement between purchaser and manufacturer do not
invalidate compliance with this Standard.

Does the above allow having a shorter hub length (dim Y, fig 5 through 15)? If so, how much shorter is acceptable.

 

RE: Use of unlisted materials in ASME B16.5 B16.47

svi, it apperas to me that shorter hubs are not permitted, subject to tolerances, see 7.4

Regards,

Mike

RE: Use of unlisted materials in ASME B16.5 B16.47

(OP)
I learned why TDW had to use a configuration wherein they used a class 150 ASME B16.47 Ser A flange with hub welding end of 9.5 mm. They trimmed of 27 mm length of the hub length to arrive at the taper section of the hub. The hub end at this location was bevelled to join a split tee half flared end of 20 mm. The flange end has a thickness of 15 mm. This is done so as so to maintain the bore of pipe at ID = OD - 2x9.5. If that is not the case, they will have to custom forge a flange to the dimensions needed. A thicker flange of the 15 mm hub welding end thickness will have the bore reduced from that of the 9.5 mm pipe wall thickness. The additional thickness on the hub is required to stiffen the split tee neck against the weight of the drilling machine.

A flange design check was made using the ASME Sec VIII Div 1 App. 2 for the changed hub length. The flange design failed for longitudinal stress at hub small end. Even the standard flange was failing for this calculation. A standard flange does not need to be qualified by a calculation.

Eventually the TDW fitting was accepted by the owner company based on that TDW fittings have been used without problems.  

RE: Use of unlisted materials in ASME B16.5 B16.47

svi, appreciate the follow up.

Interesting that though a thing may not satisfy a calculation regarded as generally aplicable, it still works. Maybe tells more about the limitations of some of our calculations than anything else.

Regards,

Mike

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