Fitting Set back

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15 years 10 months ago - 15 years 10 months ago #4644 by 11echo
Replied by 11echo on topic Wayne ...I'm sorry I don't
Wayne ...I'm sorry I don't have anything on tee’s; I'd guess they wouldn't be too far different from the SR ell dimensions. …Good Luck my friend!

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15 years 10 months ago - 15 years 10 months ago #4647 by zac
Replied by zac on topic Wayne ...I'm sorry I don't

Wayne ...I'm sorry I don't have anything on tee’s; I'd guess they wouldn't be too far different from the SR ell dimensions. …Good Luck my friend!


hello mark, Good day to you, would you mind if i ask if the table you shared for set back dimension for slip on flanges are supported by any standard? say for example in ASME guide? please let me know for any article that support this table.
thanks a lot, hope to hear any message from you.

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15 years 10 months ago - 15 years 10 months ago #4648 by Jop
Replied by Jop on topic Zac, I am sorry but
Zac,
I am sorry but I do not think you (or anyone else) will be able to find this issue in any of the existing Codes.

So! how is it set?

A Slip-On Flange will come in different Flange Ratings. But the Flange Rating has nothing to do with the placement.

A Slip-On Flange can be put on most of the fittings that are commonly used in a piping system. But the fittings themselves has little to do with the placement. The only impact the fitting has is on Short Radius ELLs and some TEEs where two Slip-On flanges might run into each other.

So, what is the Setback or Placement Criteria based on?

The set back dimension or placement criteria is based on the desire to avoid causing damage to the Gasket surface or contact face of the flange.

To do this the setback is constructed based on the wall thickness of the pipe (or fitting) the Slip-On flange is attached to. The weld that attaches a Slip-On Flange to another object is a Fillet weld. The Fillet weld size criteria in this case is equal to the wall thickness of the pipe or fitting. You then add 1/8" for additional clearance set-back to insure that weld spatter does not damage the Gasket Face.

So if you are attaching a Slip-On Flange to a pipe (or fitting) with a 3/8" wall you would add the 3/8" wall to the 1/8" clearance set-back and have the 1/2" placement shown for some of the examples in the chart above.

The Mega-Engineering companies of the world do not want every Tom, Dick, Mary or Larry wasting time doing these calculations every time a Slip-On flange is required. First it would be highly prone to error. Second, it is a waste of time. It also leads to conflict between the Designer who uses his own criteria and then a Checker who uses a different criteria.

What they do is create a chart like the one above, they double and triple check it and then finally issue it to all piping designers as the Company Practice. You used it (Designers and Checkers alike) or justified why you could not or would not use it. In most all cases the company won all the arguments or discussions.

Do it once and Do it Right

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15 years 10 months ago - 15 years 10 months ago #4649 by zac
Replied by zac on topic Zac, I am sorry but

Zac,
I am sorry but I do not think you (or anyone else) will be able to find this issue in any of the existing Codes.

So! how is it set?

A Slip-On Flange will come in different Flange Ratings. But the Flange Rating has nothing to do with the placement.

A Slip-On Flange can be put on most of the fittings that are commonly used in a piping system. But the fittings themselves has little to do with the placement. The only impact the fitting has is on Short Radius ELLs and some TEEs where two Slip-On flanges might run into each other.

So, what is the Setback or Placement Criteria based on?

The set back dimension or placement criteria is based on the desire to avoid causing damage to the Gasket surface or contact face of the flange.

To do this the setback is constructed based on the wall thickness of the pipe (or fitting) the Slip-On flange is attached to. The weld that attaches a Slip-On Flange to another object is a Fillet weld. The Fillet weld size criteria in this case is equal to the wall thickness of the pipe or fitting. You then add 1/8" for additional clearance set-back to insure that weld spatter does not damage the Gasket Face.

So if you are attaching a Slip-On Flange to a pipe (or fitting) with a 3/8" wall you would add the 3/8" wall to the 1/8" clearance set-back and have the 1/2" placement shown for some of the examples in the chart above.

The Mega-Engineering companies of the world do not want every Tom, Dick, Mary or Larry wasting time doing these calculations every time a Slip-On flange is required. First it would be highly prone to error. Second, it is a waste of time. It also leads to conflict between the Designer who uses his own criteria and then a Checker who uses a different criteria.

What they do is create a chart like the one above, they double and triple check it and then finally issue it to all piping designers as the Company Practice. You used it (Designers and Checkers alike) or justified why you could not or would not use it. In most all cases the company won all the arguments or discussions.



Hello Mark,

I was surprised with your reply, i never expect that someone like you would give that very imfomative thoughts. Any way you are precisely correct, im so thankful for that information, its just that i was not able to fully read and understand about the content of the table, then lately i noticed that you mention in your reply about ASA which stands for American Subcontractors Association if im not mistaken.

I tried to access their libraries, with regards to their expertise in construction technique, but i failed to. Im not sure if your one of the member of the organization.

Actually im new to the piping industry, an to be honest with you, we never practise this table......a couple of hours ago, we have an arguments with our superior as i introduce the subject, then i present to him my cross checking of the datas, an it seems that he keep quite.

Thank you very much for the information Mark, i was just so happy reading your reply... i just want to know more about piping construction technique, an i do believed that ASA has a lot of construction practices which could not be found on any standard codes. I wish to know them, like the table that you recently shared.

God bless you and more power

Best regards
zac

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