help !!! 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)

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 This email address is being protected from spambots. You need JavaScript enabled to view it. and ask for the]"Quick Worst Case Flange Extension Chart"[/color]