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Distance from Flange to Pipe

Distance from Flange to Pipe

Distance from Flange to Pipe

(OP)
Can anyone give me the following info: (PIPE SCHEDULE 80, Carbon Steel, Flange RF CLASS 150, Process TEMP 100 C, Pressure 7 BAR)
1.For a 1 ½ Pipe with a 1 ½" Flange welded on it- what would be the distance between the pipe and the flange.
2.For a 2" Pipe with a 1 ½" Flange welded on it- what would be the distance between the pipe and the flange.
3.For a 4" Pipe with a 1 ½" Flange welded on it- what would be the distance between the pipe and the flange.
4.For a 6" Pipe with a 1 ½" Flange welded on it- what would be the distance between the pipe and the flange.
5.For a 8" Pipe with a 1 ½" Flange welded on it- what would be the distance between the pipe and the flange.
6.For a 10" Pipe with a 1 ½" Flange welded on it- what would be the distance between the pipe and the flange
 

If the Flange size is 2" will these distance vary.

 

RE: Distance from Flange to Pipe

vds002,
Your approach for connecting small branches to larger headers is not consistent with normal industry standards.

Is there a reason for this?

Except for the 1-1/2" and 2" headers the normal industry standards for small branch piping like this would be.
For 3" and larger headers:
- 1-1/2" Sock-O-Let, a 4" long Nipple(PBE) and a Socket-weld Flange.
or
-1-1/2" Thread-O-Let, a 4" Nipple (TBE) and a Screwed Flange

With 2" branches the same applies.

The stand-Off dimension for these is easily calculated.

For the 1-1/2" header you should use a standard size to size TEE, a Nipple and a Socket-Weld Flange or Screwed Flange.

For the 2" header you should use a Reducing TEE and then a nipple and then the Socket-Weld flange or Screwed Flange.
 

(PBE) = Plain Both Ends
(TBE) = Thread Both Ends

RE: Distance from Flange to Pipe

vds,

It would probably help you a whole lot in seeing what you need to do, if you could first manage drawing those things to something like a proper scale.

**********************
"Pumping accounts for 20% of the world's energy used by electric motors and 25-50% of the total electrical energy usage in certain industrial facilities."-DOE statistic (Note: Make that 99% for pipeline companies) http://virtualpipeline.spaces.live.com/

RE: Distance from Flange to Pipe

(OP)
Pennipper...I truly appreciate your input....I am trying to size the length of thermowells that are going to be installed on a 1 1/2" ,2", 4", 6", 8", and 10" pipes. The thermowells are flange type.
1. I need to know the distance from the flange to the pipe to calculate the total length of the thermowell.
2. What I am trying to ask is as a standard practice how long is the nipple which is used to weld/screw the flange to the pipe.
3. You mentioned that connecting small brances to long headers is not good. Can you tell me what would a industry standard branch be for these pipes.
4. What kind of flanges should be used on the pipe (weldneck or slip on or any other you suggest)
thanks again.....vds

RE: Distance from Flange to Pipe

vds002,
Do you not have basic fitting charts that give the dimensions for fittings such as "O-Let" fittings, and Flanges?
If not, Here is the link for the "O-Let" fittings:
http://www.bonneyforge.com/OletCat.PDF

And here is the link for Flanges:
http://www.texasflange.com/Dimensioncutsheet.htm

If you are not a piping Designer you should find one and have him or her work out the dimensions for you.

It is not hard to select the right Thermowell lengths.  They only come in a limited number of sizes.  They are based on the "U" dimension (the penetration) and the Stem Length (the depth of the "Pocket" the Instrument is inserted into).  
Here is a link for the Thermowell:
http://www.thermowells.com/thermowellspage8.html

You will normally only get people here to advise you what to do and how to do it but we/I will not normally do the work for you.  The reason why is that If we/I make a mistake we/I do not want you to blame us for getting someone hurt or killed.

I hope you understand.

RE: Distance from Flange to Pipe

(OP)
sorry for poorly presenting my question. I am not tyring to get my work done by others. I was just trying to get some info on industry standard practices for piping. I am a fresh grad inst engg and we dont have a piping engg in our company whom i can ask these questions. All i am trying to find out is what is industry practice for branch size for particular pipe diameter. Can pipe from 1 1/2"-10" have 1 1/2" branch. If not how does branch size split with pipe dia range.
Second thing is what is the nipple size (standoff distance) used for welding/threading the flange to the pipe.
Hope I am not being too unreasonable in asking these questions. appreciate ur inputs.

RE: Distance from Flange to Pipe

Vds002,
Sorry I got so wrapped up with the answer to #1, I forgot to answer all your questions.

Your question #2
You should use a Nipple with a minimum length of 4" because there will be the standard Thread engagement (or Socket engagement) on each end.

Your question #3.
The standard method for small branches (1-1/2") to a header 3" and larger would be an "O-Let" fitting

Your question #4.
If your basic Line Class Piping Spec has threaded connections for all small pipe joints then you would use a Screwed Flange.

If the basic Line Class Piping Spec has Socket Weld connections for all small pipe connections then you would use a Socket Weld Flange.

RE: Distance from Flange to Pipe

vds002,

From my experience, the standard distance from pipe O.D. to face of flange is 6" for flanged thermowells. This information should be available through some kind of client standard. If you are trying to purchase thermowells based on this information, don't... You should have a copy of the piping drawings or details which clearly show this distance.

Good Luck!

Hench   

RE: Distance from Flange to Pipe

It depends.
(I hate that answer).

Some clients specify 6-inches from flange face to top of pipe.  Unfortunately this is not normally a requirement.

If no client standard exists then you need to see the piping isometric or get the details from the piping designer.  I recently obtained information from a designer on a NPS 3 line or so.  He used a tee to a NPS 2 connection then a swage reducer from NPS 2 to 1 1/2 then a threaded flange.  The old client spec permitted the threaded flange instead of requiring a weld-neck flange.  Get the information from the piping designer; or select a 7 1/2-inch maximum insertion regardless of the other details.  Obtain the likely fitting dimensions and sketch to assure that you don't need something shorter.

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