Weldolets – Matching Per Flange Material 2

[PositiveRate]

This is my first post, so please comment if you see anything amiss on how or what I present in my question.

My question is regarding Weldolets® and Sockolets® and piping materials in a piping specification. Usually, the forged materials specified for flanges and olets are the same from 0.5" NPS to 24" NPS, for example ASTM A105. But I have a piping specification that doesn’t follow that convention. The general particulars for this pipe spec are design press of 1,480 PSIG @ 100°F, design temp of -10°F/+220°F with a service in fuel gas and gas lift operations. Designed to ASME B31.4/B31.8 (D.F. = 0.72) and a corrosion allowance of 1/16". The flange material is specified but the olet material is not, so I plan to follow the flange material unless there is a reason not to.

Pipe Size    Pipe Material              Schedule   Flg Material
----------   ------------------------   --------   ------------
0.5" - 2"    API-5L Gr B, SMLS          Sch XS     ASTM A105
3" - 8"      API-5L Gr B, ERW or SMLS   Sch STD    ASTM A105
10"          API-5L X42, ERW or SMLS    Sch STD    ASTM A694 F42
12" - 14"    API-5L X52, ERW or SMLS    Sch STD    ASTM A694 F52
16"          API-5L X52, ERW or SMLS    Sch XS     ASTM A694 F52
18"          API-5L X52, ERW or SMLS    Sch 30     ASTM A694 F52
20"          API-5L X52, ERW or SMLS    Sch XS     ASTM A694 F52
24"          API-5L X52, ERW or SMLS    Sch 30     ASTM A694 F52

All of that is to get to this question regarding the material choices for the Weldolets® and Sockolets®.

For an 18" x 3" Weldolet®, would the material match the flange material associated with the pipe header? For example, the bill of material for that size would specify:

[highlight #FCE94F]WELDOLET, SCH 30 X SCH STD, ASTM A694 F52[/highlight]

But for an 8" x 3" Weldolet®, you would specify:

[highlight #FCE94F]WELDOLET, SCH STD, ASTM A105[/highlight]

Is this correct?

Thank you for your thoughtful consideration.

PositiveRate

 

[1503-44]

Pipeline codes B31.4 & 8 I use MMS specs for high strength flanges and fittings to match pipeline pipe strengths.

https://www.octalpipefittings.com/mss-sp-75-wphy-fi

High Strength Steel Fittings spec MMS SP-75, WPHY-52, 60, 65 etc.

https://www.metallectsteel.com/mss-sp-75-fittings.html

High Strength Steel Flanges MMS SP-44, F-52, 60, 65 ...

http://pipe-flange.com/pdf/ANSI B16.47 FLANGE.pdf

A black swan to a turkey is a white swan to the butcher ... and to Boeing.

 

[LittleInch]

I think the weldolet would need to follow the branch pipe material more than the header pipe as the additional welding makes u up the strength difference, but not the branch.

However the pipe size up to 8~" is grade B, so A105 should be good for those sizes. Only if you get a branch connection >8" would you maybe need to look at the A694 spec.

Also maybe you know, but if you're using A694, you need to specify the flanges to MSS-SP-44 for the flanges , not B16.5, and MSS-SP-97 for the branch fittings.

I'm happy to be proved wrong....

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

 

[1503-44]

OK. A-105 is low yield strength at 36000 psi. Closely matching wall thicknesses with x52+ isn't going to be easy. It's also better to weld similar strengths. Kind of a large gap from 36 to 52. I always used a pup of x42 in between.

Pretty sure you can still just reference the MSS and the desired strength and leave the actual selection of astm material to the mfgr.

http://www.metalsflange.com/astm-a105-flanges/

A black swan to a turkey is a white swan to the butcher ... and to Boeing.

 

[MJCronin]

Positive ...

A very good piping question and very clearly stated !!!! ....... Sadly, this is a rare thing on these august fora

In my opinion, this entire discussion outlines the importance of companies supporting "up-to-date" piping specifications....

My experience has been too many projects just copy and reuse the same decades old piping specifications..

Field engineers should not be making these important design decisions .... The world changes and piping specs must be kept up to date !!

But dismissal of the old grey-beard staff engineer is usually the first target of new MBAs ....



MJCronin
Sr. Process Engineer

 

[GBTorpenhow]

The default assumption of reinforcement is usually that the reinforcing material is at least as strong as the header being reinforced, so in my mind matching the higher yield of the two header and branch materials is the inarguably conservative approach.

When I used to do B31.8 work for 2" and smaller branches I would use 3M or XS A105 (or A350 LF2 CL1) olets exclusively regardless of the header yield, but this was meter station work with DF = 0.5 so no reinforcement calcs required by B31.8 for any reasonably large header size. Transmission/distribution companies around here typically do not allow weldolets above 2" but if I was in your position I would start by using your proposed approach until a reputable olet manufacturer told me in writing otherwise.

 

[LittleInch]

The question also needs to be asked is what does your piping spec say about when / what size do you change from weldolets to reducing tees?

Big weldolets are not often used because they take forever to weld and you end up with so much heat going into the header than you can bend it like a banana.

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

 

[1503-44]

I've always had the 2" max weldolet size limit that GBT mentioned at the gas companies I worked for too. Weld in with reinforcing saddles for larger sizes, or tees and reducers, if the right sizes were available.

A black swan to a turkey is a white swan to the butcher ... and to Boeing.

 

[GD2]

PositiveRate,

You would most likely be using MSS-SP-97 weldolets of ASTM A234 material of suitable grades to match X42, X52 Pipes and A105 for Gr. B

GDD
Canada

 

[1503-44]

Basic Yield of A234 is 35 ksi
WPB 32
WPC, WP11CL2 40
WP11CL1　30
WP11CL3 45

http://blog.sunnysteel.com/standard/astm-a234-standard-specification/

A black swan to a turkey is a white swan to the butcher ... and to Boeing.

 

[GBTorpenhow]

You would most likely be using MSS-SP-97 weldolets of ASTM A234 material of suitable grades to match X42, X52 Pipes

I would disagree with this statement (emphasis mine). As I recall WPB (35 ksi) and WPC (40 ksi) are the only grades of ASTM A234 plain CS material, the rest are alloy steel. I believe PositiveRate has the appropriate A694 material designated in the original post.

While for a 35 ksi yield olet it is not necessarily incorrect to specify A234 WPB, it is in my experience standard practice to specify a forged material designation (A105) for forged fittings (or fittings wrought from forgings) and reserve A234 WPB for fittings constructed of wrought pipe/plate such as buttwelding elbows/tees/caps/reducers, swages, etc.

 

[1503-44]

No problem welding A234 to 5LX-42 or lower.

The astm material does not have be specified when ordering with the MSS-SP spec. You need only specify your required yield stress. But nothing wrong about specing the material if you want to.

A black swan to a turkey is a white swan to the butcher ... and to Boeing.

 

[GD2]

After all the good discussion, I agree with what PositiveRate had suggested. He had correctly selected the olets.

GDD
Canada