Tantalum Tubes for shell and Tube HX- code and Testing Info

[mechmania]

Hello All,

I am a Green Horn, Mechanical Engg.(10 month old in Proff.career). I am preparing Eng-Specification for the shell and Tube Heat exchanger.

This one is small size exchanger(AEL Type-Shell & tube 1 Pass each) ( over all Surface area 143 sq.ft) w/Tube Length 10 ft , No of Tubes =109) Design temp= 250 dg F and Design press= 150 psig /FV(shell side) & 150 psig (Tube side).

Material's are as follows:

Tubes: Tantalum
Shell: Carbon steel
Tubesheet: Haste alloy C276 (Claded with Tantalum)
Flanges & Channels: Haste Alloys w/ Tantalum Liner

Here are the Array of questions:

1) What should I include in my Eng-Spec as far as testing for the Tantalum tubes are concern. What are the important point’s should i need to include in my specification, concerned to the Tantalum Tubes Testing, Welding. Is there any special procedure that I need to include in my specification?

2) I am looking at two options for Tube sheet?
* Clade the Haste alloy C276 Tube sheet w/ Tantulum
* Is it okay to weld overlay to the Tube Sheet instead?
* Lines the Tube sheet w/ Tantalum (Is this same as cladding??)

Which option is much better and cheaper?

Please Guide.

Thanks a lot in advance.
Mechmania

 

[metengr]

1) What should I include in my Eng-Spec as far as testing for the Tantalum tubes are concern. What are the important point’s should i need to include in my specification, concerned to the Tantalum Tubes Testing, Welding. Is there any special procedure that I need to include in my specification?

For your engineering specification, you need to be specific regarding tube material. Reference an ASTM material specification (for example ASTM B521-98) which is "Standard Specification for Tantalum and Tantalum Alloy Seamless and Welded Tubes”. Purchase and review this Standard Specification carefully - if you have any supplemental requirements you may want to consider invoking them in your Specification.

I am looking at two options for Tube sheet?
* Clade the Haste alloy C276 Tube sheet w/ Tantulum
* Is it okay to weld overlay to the Tube Sheet instead?
* Lines the Tube sheet w/ Tantalum (Is this same as cladding??)

A weld overlay on the tubesheet would be my preference over cladding. Explosive cladding may be an option. Will the Ta tubes be seal welded to the tubesheet?

I would suggest you contact one or more chemical heat exchanger references to provide input to your specification.

http://www.titanmf.com/products/chemical/

dynamicmaterials.com/data/brochures/8-Wah Chang Zr clad paper 8-99.pdf

http://www.stoneprocess.com/

http://www.princetoninternational.com/heat_exchangers.htm

 

[EdStainless]

One other point, stop using trade names. Hastelloy belongs to Haynes, and to be correct, when you use it you are saying that they must supply the metal. These alloys have UNS numbers. Learn them and use them.

All of the Ta units that I have seen were explosive bonded.

= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection

http://www.trent-tube.com/contact/Tech_Assist.cfm