Cladding or Lining? 1

[Gmustin]

I am designing a 48" O.D. x 18'0" long vessel.
F&D head on one end and an eccentric cone 48"O.D. x 30" O.D. w/ 30" flange/bind at the other end.

The customer is requiring CS shell/head with 1/8" SS Clad or Lining.

design data is:
150psig/FV @ 450deg F
1/8" CA

My question is with this having full vacuum will it require clad overlay or explosion bonded clad plate? or will a standard lining be suffecient?

Thank you in advance for your insight and help.

 

[vesselfab]

ALL DEPENDS.

If it were me, i would go with eplosion bonded clad.

Weld overlay is time consuming and lots of NDE.

BUT if you have heavily loaded internals that require welding to base metal, you may want to overlay instead of stripping out all that clad.

Not sure what you are calling a standard lining, assuming strip lining, is not good for vacuumn service without plug welds all over.

clad is the easiest fastest way.

 

[Gmustin]

i was referring to strip lining and plug welding.

i was thinking going with the explosiion bonded plate also, i just wanted confirmation.



my next question is when using software (compress) how would you input the clad material? would i run it at SA-516 gr70 with NO corrosion allowance since the clad is only for corosion? or do i need to use the 1/8" CA in compress and manually input the clad specs?

 

[SnTMan]

Gmustin, I would normally disregard the clad, use base metal dimensions w/ zero corrosion. That way if you care about MAWP's they will be correct. If treating the clad as corrosion allowance the N&C MAWP's will be incorrect.

If considering the strength of the clad there are additional requriements to be met in Part UCL.

Regards,

Mike

 

[Gmustin]

thank you everyone for the insight.
i had some doubts on what i planed on doing on this project because i have not worked with claded vessel's alot. but you guys confirmed that i am going in the right direction.
thank you

 

[ak1965]

Gmustin

My expereince with Clad Veesl is very good. Liner vaessels pose many diffculties right from fabrication, NDT & during leaks as well. Weep Holes provided for Leak detection get choked many a times.

Explosion Cladding vessels are the best, economical, more reliable (if cladding done repsoisibly) & easy for in-service inspections.

 

[Guest102023]

What is the thickness? You might find solid stainless is more cost-effective, and much simpler to fabricate. You can also consider clad shells and solid SS heads if thermal cycling will not be severe.

 

[Gmustin]

i wanted to use solid SS because it would be alot more cost effective and simpler to fabricate, but the customer does not want solid SS construction for some odd reason.

the material thickness that i am coming up with is 5/8" thk SA-516 GR70 with 1/8" SA-240 316L clad. 3/4" total thickness



my next problem/question is...
during fabrication using the clad plate, how do i keep the SS from carbon contamination? mainly when beveling and welding

 

[r6155]

For this pressure vessel with solid SS plate ( no clad ) the thickness should not be greater than 10 mm ( Joint E=1)

Regards

r6155

 

[Guest102023]

The customer is wrong, and wants to overpay for less corrosion resistance. Hands down it is cheaper to build solid SS.

 

[Gmustin]

i know..
but at the same time, "the customer is always right"
i have already told the customer SS is alot cheaper and faster to build. but they dont care.. makes no sense to me, and they didnt give me a reason other then thats what they want.. lol

 

[Guest102023]

Does anyone actually supply SS clad CS plate at that thickness?

 

[Gmustin]

yes, i just got a quote back yesterday for the explosion bonded plate needed for the whole job.
leed time on the shell plate is 8 weeks, leed time on the head is 14 weeks
DMC clad

 

[steris]

I would also suggest looking into roll clad plate. We use a lot of it for material that is too thin for explosion clad. We use nickel 200 roll clad onto steel plate and the thickness tolerance and flatness is much better than explosion clad plate.

 

[moltenmetal]

There are situations where SS clad CS is safer than solid SS and hence worth the effort, even for a small vessel. Just so you know-

 

[rustbuster]

With regard to welding, complete the CS first then carefully prpare the ss by grinding the edge. Use copper sulphate to test for and remove the contaminants the finish the weld with 309 filler.

 

[Jaketman]

I would avoid strip cladding if possible. It is a maintenance nightmare if your welds fail (i.e. due to fatigue). As cladding is used for corrosion resistance, any product that gets under the cladding will fill in underneath the loose clad and present a difficult corrosion problem where the repairs are not easy.

As for as welding, there is no issue with welding CS to Stainless, but of course, a contaminated weld will not provide as much corrosion resistance as the clad, and may be selectively attacked. Perhaps increasing the metallurgy of the weld filler can address some of the issues with weld contamination by the CS.

I am also building a cladded vessel, and will use explosion clad (preferred) or roll clad (minimum) due to long-term reliabily concerns I have seen.