Copper Tube on Pipe Rack

[Dolemite]

Good Morning,

Looking to run an 1-1/2" copper line for N2 gas. Have an existing piperack that has W8 beams on 20' centers. Just wondering if the tube will sag at this span. I can find span table for copper tube filled with water but no 'gas' span tables. Thank you in advance for your assistance.

 

[PEDARRIN2]

Per MSS-SP-69, Table 3, 1-1/2" copper tube in "vapor service" has a maximum horizontal support spacing of 10'.

 

[LittleInch]

The issue usually is what is an acceptable deflection. What appears to be horrible to look at will still be within buckling or stress limits so you need decide what is the maximum sag you want to permit.

A 1 1/2" pipe at nigh on 6m will have a visible sag, but is this acceptable to you?

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[EdStainless]

Which grade of Cu tube (wall thickness) is it?
I would go with supports at 10' for this, the risk of buckling is not fun.

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P.E. Metallurgy, Plymouth Tube

 

[Dolemite]

Many thanks to all. At 20' spans between supports, I am so far off from the recommended 10', that I will look to put some support steel, spanning between the existing supports. This won't be cheap.

I can rout the pipe another way (thru an existing building) and minimize the run on the rack where the new steel is required. I'll be on the rack for 140' instead of 800'

The issue here is we have a building that needs N2 gas but not enough usage to justify its own permanent tank outside. And too many safety concerns to run off cylinders.

I appreciate all the help!

 

[EdStainless]

What would it cost to run this line in stainless steel?
The existing supports would be fine for that (1.5" x 0.065" 304L).
You can use sanitary tubing (like they use for food processing), these lines go in all orbital welded.
This is welded tube made to ASTM A270.
You wouldn't need the great surface finish, standard 25Ra would be fine.
We ran all of our gas lines in SS, but then we make it

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P.E. Metallurgy, Plymouth Tube

 

[Dolemite]

The cost of using SS tubing would be much cheaper than the cost of adding structural steel to the 7 existing supports! I'm surprised that the same diameter SS tubing can make the 20' span! Thank you for the great idea!

 

[Gator]

Is there a reason you're not using carbon steel?

 

[Dolemite]

The company has pipe specs for the various utilities. The pipe spec for N2G is copper until it gets to the filter (say before process equipment)and then stainless. Pharmaceutical.