slug catcher material proposal

[johnthebest]

as a client we specified the use of CS + 316L SS clad for the Slug Catcher and All ferritic materials shall be supplied in the normalized condition.

The contractor proposed "SA 537 CL.2 + SS 316L SS Clad". SA 537 CL.2 will be quench and tempered (Q&T) as per ASME SEC II part A Ed.2017 and the tempering temperature for Class 2 plates shall not be less than 1100°F [595°C]. Q&T heat-treated material is also accepted as per UCS-23 of ASME SEC VIII Div.1 Ed.2017 and Table 3-A.1 of ASME SEC.VIII Div. 2 Ed.2017. This has been proposed based on allowable stress at design temperature 90°C for SA 537 CL.2 material which is significantly higher than other materials like SA 516 GR. 70 and SA537 CL 1.

what are your thoughts?

 

[weldstan]

Have specified 537 in similar applications to reduce wall thickness and costs for thickness > 2".

 

[johnthebest]

@weldstan
Thx for your reply. Can you give me more information about the caebon steel grades used in slug catchers

 

[weldstan]

I can only state that we specified SA-516-70 for one and SA 537 for a 4" wall slug catcher but that was 40 years ago.

 

[cap1a79]

I think it would be helpful to make the issue more simplified...

1) Some of the owner specs has "normalized" condition of CS. What do we expect mostly? (ex., A516 Normalized, A537 Cl.1)
--> By the normalizing process, one of the advantages for the heat treatment is to get "improved toughness at low temperature" by normalized grain size.

2) Then, what do we expect Q&T grade (ex., A537 Cl.2)
--> By quench & tempering, improved mechanical properties & fatigue resistance can be achieved.
--> However, the evaluation of low temperature embrittlement is required.

I believe A516 & A537 Cl.1 are more common while the use of A537 Cl.2 may require client approval based on company's spec due to the concern of grain size.

Lee SiHyoung,
WorleyParsons Oman Engineering,