45 degree latrolets...some questions

[JAYDEE23]

I have searched and come up with nothing on latrolets concerning weld sizes. I am trying to prove to a colleague that using a 1" sch 160 latrolet on a 20" sch 40 pipe is not the way to go. (Because thats the way they always did it)

Calculating branch wall thickness required per B31.1 we could get away with using a schedule 5S. Why the heck would we use a schedule 160!

Also i am having no luck finding end weld sizes for latrolets in general. Any insight into this? My concern comes from the attached picture for both these points.
(picture is of a sch 160 latrolet)

 

[ione]

Take a look to this

http://www.bonneyforge.com/specs/branch/latrolet.cfm

 

[Giuliano81]

Take away that latrolet and weld a weldolet then go on with a 75mm nipple and 45° elbow.

It's much stronger configuration than that seen on the photo.

I hope I gave you an idea.

Regard
Giuliano

 

[JAYDEE23]

ione
Ive looked at that chart closely. From what i can tell there is no way to deduce weld size from the given dimensions.

Giuliano81
Unfortunately we currently need a 45 degree entrance in to the run pipe. I am looking into changing that also..

Thanks for the responses..

 

[JAYDEE23]

Regarding the bonney forge catalog, the diagram for welding latrolets seems to differ from the actual product in that the diagram shows the weld line parralel to the run pipe when in actuality the weld line is not...see picture

 

[Hench]

Have a look at the attached. These are pages 34 and 35 out of the Bonney Forge catalog.

Good Luck!

Hench

 

[Hench]

oops!

Trying this again....

Have a look at the attached. These are pages 34 and 35 out of the Bonney Forge catalog.

Good Luck!

Hench

 

[JAYDEE23]

I do appreciate the feedback. Ive looked at these catalogs.

If there is something i am missing here please point it out. Did you see the picture of the latrolet i posted? There is nothing in these catalogs that looks this way.

Until these came in i had no idea the amount of weld these would take to attach to the pipe.

 

[StoneCold]

JayDEE23
I think if you look at the welded photos, they are expecting you to fill up the entire bevel. I have never ordered the 45's and I usually stick with the sch 40 weldolets, most often I use threadolets. However I do feel the same as you do that the beveled throat is way to deep and there is an excessive amount of weld required to weld them out to flush. However that is just an opinion, I have no idea what level of stress is factored into the joints.

I am eager to hear what other real users are doing.

Regards
StoneCold

 

[JAYDEE23]

Ive not chased this through the actual company yet...i am also interested. I can tell you the catalog assumes quite a large area is removed from the run pipe under the latrolet. This could be where all the additional weld required comes from?? Not sure...

 

[ione]

As far as I know, for those fittings the weld amount should be determined by the welding bevels on the fitting. The design of this stuff should be based on compensating the metal removed from the run pipe, where the max stress concentration would occur.

 

[MBlackman]

Jaydee
Use the appropriate fitting and wall thicknesses as designated by your pipe spec. Heavy wall thicknesses are often specified for small bore piping for mechanical strength reasons rather than pressure capacity. Presuming Sch160 is specified for your 1" piping, the appropriate fitting would appear to be a 20"x1" Sch40 x Sch160; this is not the same as just a Sch 160, it will be lighter.

 

[eadwine]

Ever seen operators and mechanics climbing in the Racks and Pipeways? Now what kind of a bending moment is required to snap off a latrolet at 5S as opposed to sch.160? And remember, this line is in operation. Hmm... also remember, Murphy works here.

 

[JAYDEE23]

Thanks guys...good points...that Murphy !!!...I dont like him