Double Pipe Heat Exchager design Code 5

[BENSMIL]

Hi,

What are the typical design codes applicable for mechanical design of double pipe heat exchangers?
Are they built to confirm to ASME Sec VIII?

Thanks,
Benoy

 

[moltenmetal]

A double pipe heat exchanger is a piece of jacketed pipe, designed and fabricated in accordance with the applicable piping code- unless it is of volume/pressure/dimensions requiring it to be classified as a Section VIII vessel.

 

[Montemayor]

There is no "code" for designing or fabricating a double pipe heat exchanger.

As Moltenmetal states, the usual practice is to treat such an assembly as piping and falling within the applicable piping codes and specifications.

 

[SNORGY]

I am glad people see it that way.

So...now a guy draws the pipe-in-pipe heat exchanger on a PFD or P&ID and assigns a tag number and a duty to it. The Mechanical guy then goes and prepares a data sheet and goes for inquiry on it. A purchase order ends up being awarded to a heat exchanger manufacturing shop who happily puts a U-stamp and a nameplate on it ant registers it with the local authorities as a pressure vessel or heat exchanger with a single tube in it.

I don't know if that is funny or stupid, but it's reality.

 

[Latexman]

Here's how it happens in my little world:

So...now a guy draws the pipe-in-pipe heat exchanger on a PFD or P&ID, designs the exchanger (the duty is documented here), assigns a minor equipment number, creates a one page mechanical spec. with sketch (no duty), faxes it to his piping contractor (the contractor knows the piping specs), gets a quote, requests a PO, contractor builds the heat exchanger, inspects exchanger, witnesses pressure test, and the contractor installs it.

Good luck,
Latexman

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[crash2455]

As has already been stated jacketed pipe doesn't normally need to be code stamped. Depending on the properties of the process and heating medium JP can often fall under ASME B31.3 if you are looking to a code for guidence.

 

[SNORGY]

I like Latexman's little world better.

Basically because it's right.

 

[TD2K]

Latexman must have more clout than I do, I can't quite see selling that approach to the other groups in my company .

 

[Latexman]

I am in the Business Unit; not in the Engineering Department. That tends to give me an extra stripe on my sleeve. However, Engineering will not let me do something stupid! We do follow the Codes and Laws of the lands.

Good luck,
Latexman

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[crash2455]

Latexman's world sounds great...as long as you don't work for the company that he is hiring to build the jacketed pipe :-/

 

[MortenA]

Latexman also know some "ol' fashioned vendors" - note some that still has a fax and actually checks it

 

[zekeman]

I don't think I like Latexman's little world.
Too much dependence on "contractor" without apparent oversight.
And no RFQ's?

 

[moltenmetal]

Latexman's little world and my little world sound similar. Nothing here that is non-code gets a code stamp, and nothing that is sub-ASME gets an ASME stamp, unless a client insists. Then they get, and pay for, what they want.

Another benefit is that the fabricator of double pipe or tube in tube units is typically us.

 

[Latexman]

CSI

Good luck,
Latexman

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