there....do you have table for standard pipe to pipe spacing

If you click the "Tools" button (above), then click the small "piping" heading, you will see pipe spacing charts for both welded and flanged piping.

Hope that helps.
Anton

riz_john,

It is always helpful to know, understand and remember the basis for line spacing. Different engineering companies and owner(client) companies may have their rules but the most common minimum pipe spacing rule is as follows:
- Flange-to-pipe + clearance (+ insulation if any)

This means:
For hot insulated lines, line spacing includes 1/2 the O. D. of the flange for one line (largest if different sizes) + 1/2 the O. D. of the other pipe + 25mm (1") + the thickness of the insulation on the smaller line (if any)

(Note: There can be an exception to this Rule. See additional comments below)

Cold insulated line), line spacing includes 1/2 the O. D. of the flange for one line (largest if different sizes) + 1/2 the O. D. of the other pipe + 25mm (1") + the thickness of the insulation on the flange + the thickness of the insulation on the smaller line

Notes:
1, It is common practice to always stagger flanges when ever possible.
2, It is common practice to insulate the pipe in hot servics and leave the flanges bare.
3, It is common practice to insulate both the pipe and the flanges in cold services.

In cases where flanges cannot be staggered then the rule is adjusted as follows:
- Flange-to-flange + 25mm (1") (+ any insulation on the flanges)

i would like to thank all of you, for answering my questions and sharing your knowledge to a rookie like me.....

you guys are really great help......my best regards to all of you!!!!

good luck and more power

The comments I made above were correct but incomplete therefore could be misleading.

The statement I made was "take 1/2 the flange diameter of the largest line."

This is not always correct. You should take 1/2 the flange diameter of the flange that has the greater flange width or extension. The extension if a flange is equal to the radius of the flange minus the radius of the pipe.

Example:
Line (a) 24" 150#
Line (b) 8" 1500#
Which line would you use for the "1/2 flange dimension" in the calculation for line spacing?

The flange width for line (a) is 4"
The flange width for line (b) is 5.188"

If you use the normal pipe spacing rule then the flange of line (b) will hit the pipe of line (a).

I have created a spreadsheet showing the worst case flange extensions for all of the standard flange sizes and ratings.
I will be happy to send it to anyone who would like to have it.
Just E-Mail me jopennock@netscape.net and ask for the]"Quick Worst Case Flange Extension Chart"[/color]

Hello Jop,

Very interesting subject, as you said many clients have different rules, for example here in Mexico Pemex were allways content with a 2" span between the edge of the flange and the edge of the OD of the smaller pipe (plus insulation). But recently they want 3" the result is that we have to make bigger racks now, my theory about why they decided to change that rule is poor flexibilty design in past projects (oh, yes I'v seen it, and that is curiously related to other post you made in the Canada forum: http://pipingdesigners.com/wp//phpBB/viewtopic.php?t=17 )

BTW I have allways liked this forum and found usefull information, I just recently decided to post something here and stop just lurking. I really like what I do and hope I can help others to enjoy it too, with what little I have learned over the years.

Cheers!
Eliut

I have to agree with EliutBB, pipe spacing can be client driven. I had submitted a pipe spacing table to this site a few weeks ago( STILL don't see it yet Anton!!?? *G*). But this is a "worst case situation" where you’re fighting for every inch. I normally work in the oil fields, where space in normally not a problem, and I'd take my chart and routinely add an inch to every value. I also work very closely with the construction people, and designing piping systems that are unnecessarily "tight" only complicates their work. That I feel is one aspect of piping design, you can design to please the engineers, but if you can please both engineering & construction ...you've earned your pay! ...My $0.02 anyway. ...Mark

Steam headers and other hot lines tend to grow quite a bit over long distances in pipe racks due to thermal expansion so it might be helpful to take thermal expansion of adjacent lines into account when dealing with pipe spacing.

I generally use the rules of thumb as outlined by JOP and then calc thermal growth from directional anchors (or stops) as the lines "grow" into changes of direction (pipe rack turns) and allow a little more spacing as required.

great job on moderating this forum James!

Mikal

Mikal,
You are quite right about the extra allowance for thermal growth at changes in direction.
Thanks for pointing it out.

you can design to please the engineers, ... by 11echo.

___________

my take. Ive always taught that design is always about compliance, like complying to meet the Code and Specs or ensuring that the requirement related to SHE are meet or that the design was economically sound.

Pleasing the engineers ... i dont know but doesnt sound a good design practice. In if youre working in a hazardous environment, can be fatal.

juan1977 ...Not sure where you are from, but EVERY project I was on was headed by an Engineer(s). The goal of a designer is to take an engineering concept and turn it into real world design, capable of being constructed by people in the field. What I was trying to say is that a "designer" lives between these two worlds, and IF you can produce something that both worlds (Engineering and Construction) likes, I'd say you've done your job! ...I agree with you that if you only producing a design that only one side like is it rarely considered a good design.

you can design to please the engineers

The goal of a designer is to take an engineering concept and turn it into real world design, capable of being constructed by people in the field.

_______________________________

The above 2 statements are not the same. The intent of design is to ensure compliance to the requirement of the project specification and NOT to please the engineers. Pleasing the engineers is NOT the same as taking an engineering concept and turning it into real world design.

As to question of where im coming from? as a license professional engineers ive been involved in several mega-projects (costing over a billion US dollars but limited to refineries, power plant and petrochemicals) built and design by Bechtel, FD, etc in different continents for over 30 years - so the answer is from the hot desert of the arabian peninsula all the way to emerging exotic asian countries . Basically my involvement is related to code (the ASME and API and several OSHA CFR)compliance analysis/evaluation. im also cert to the bones.

"The intent of design is to ensure compliance to the requirement of the project specification" ...AND who do you think set up these requirements? ...Designers? ...Draftsmen? ...Construction people? ...Engineers set these requirements! AND if I can make them happy then I'm in "compliance" to their specifications!
The mistake you're making here is you’re taking a "part" of what I've said out of context and not looking at the whole post!
I too have some experience under my belt, from Alaska, to Pacific coast oil rigs, coal fired power plants in central U.S., to steam generation/injection in the Middle East ...That over 30 yr.s my friend & that’s been working closely with Engineers to get the job none!

Engineers may set the requirement, but compliance to the construction requirement is set by the project spec. I have never come across involving the question related to construction project where the EPC guy says i've followed the engineer instruction and if its wrong - hey blame the engineer.

The rules for construction are always written - always. And the job of a prof involving design is not to make any one happy but to ensure compliance with the stated requirement (and that its written, the ISO demand it). Been building nukes power plant, refineries and petrochem since the early 70's as an engineer (the one who affixed seal).

11echo,

I agree with your signature..........

NEVER argue with idiots!

I guess that's why you just stopped. Good for you!!