Slug Catcher according to ASME B31.3

[TSD78]

Dear Mr/Mrs,

I need your opinion. At this time our company have an option to design and fabricate a Finger Slug Catcher according to ASME B31.8 (as ussualy) or according to ASME B31.3.
If we choose ASME B31.8, the supplier/vendor sayid that the fabrication will take about 7 month, meanwhile if we choose ASME B31.3 the supplier/vendor can do the fabrication in 16 weeks but plus additional extra time, beacuse we ay need to considered other thing due to thicker pipe wall and the requirement for PWHT.
If some body have experience with doing Slug Catcher according to ASME B31.3. can you please share the experience here?
What is the advantage and disadvantage between the choise of designing and fabricate slug catcher according to ASME B31.3 copare to ASME B31.8 others than the thickness requirement.
Your opinion will be so helpful
Thank you.

TSD78

 

[pennpiper]

It might help some out here if you provided information such as:
- overall dimensions
- pipe size and wall schedule
- Material


A. I hope that you are getting bids from more than one Pipe Fabrication Shop. If not, I strongly recommend that you do so.

B. All bidders should be required to give a full detail breakdown of the schedule. The detail should include the Approval cycle for Shop Drawings, Purchase and delivery of material, Approval of Welding procedures, Actual fabrication, All QA/QC, All PWHT (Post Weld Heat treatment) if required, Painting and delivery.

C All Bidders should be required to define if & why there is a time difference between fabrication per B31.8 and B31.3.
Bidder #1 = B31.8 (28 weeks?) vs. B31.3 (16 weeks?) Why?

 

[SNORGY]

I am not sure why the difference in delivery designing one code versus the other. I would have thought that the problem would be the other way: that the B31.3 design would take longer than the pipeline code design.

If you go thick enough on the wall with the slug fingers to B31.8, it will reduce some notch toughness requirement issues on both the parent metal and the weldment. As for PWHT, I think you could probably do up to almost 1.5" without PWHT if designing to B31.8 (here I am making the perhaps totally incorrect assumption that it is similar to the rules in CSA Z662), whereas in B31.3, you would be into PWHT at about half that thickness. In either case you would need to pay attention to hardness control in the WPS / PQR.

There are no test bend requirements, presumably...so a slug finger is just a short length of fat pipe, or a long length of skinny pipe...pipe is pipe...

I personally don't see an advantage to B31.3 design here.

Regards,

SNORGY.

 

[BigInch]

I think it's that the high strength material for a 31.8 design takes longer to get your hands on.

From "BigInch's Extremely simple theory of everything."

 

[stanier]

I have seen such slug catchers designed and installed in Australia to ASME B31.3. It was inside a facility so made sense to do so. The slug catcher was buried beneath a soil mound to mitigate the fire sizing of relief valves.

Surely the local authority, insurer and end user has a say in this decision.

"Sharing knowledge is the way to immortality"
His Holiness the Dalai Lama.

http://waterhammer.hopout.com.au/

 

[DLite30]

Consider your regulatory requirements.

What DOT regulation is the pipeline subject to? 192?
If so, then it's Section 8, unless they're built out of standard pipe and fittings.