Impact test requirements for LAS

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K K

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Jul 27, 2020, 1:59:05 AM7/27/20
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Hi Experts,

"Good Morning"

My query has below.

Help me to prepare pWPS.
Process : GTAW +SMAW
Material : P.No - 5B   
ASTM A335 Grade P9.
Pipe Size - 16" Sch-60.
Thickness: 16.66 mm
Thickness range: 5mm to 33.32 mm
According to ASME B31.3 Table 323.3.1 shall I required an Impact for the above-mentioned thickness and material.
As per my knowledge, the above 25 mm impact test would be required. 
How I can find according to line class where impact test required or not.
If a minus 29° C impact test not required for LAS. 
When we shall consider the impact test exemption. 

And regarding consumable for P No- 5A 
ASTM A335 Grade P22

if I use ER90S-B3 ok or shall I use ER80S-B3 because my client suggest me to use ER80S-B3 please clarify way?

Thanks in advance 

Regards
Kiran




K K

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Jul 28, 2020, 12:42:01 AM7/28/20
to Materials & Welding
Dear Experts,

Please look into my query, please give me your response on my doubt.

Thanks
 Kiran 

K K

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Aug 18, 2020, 3:36:18 AM8/18/20
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Dear Experts,

Please I need your answer to my above query. 

My client has mentioned the above 25 mm Impact test would be required, in accordance with B31.3.

Question: Are materials, for which a temperature of −20°F (−29°C) is listed in the Minimum Temperature column of
Table A-1, exempt from impact testing for any combination of thickness and temperature above −20°F (−29°C)? Reply: Yes.
The minimum temperature in our scope is not below minus 29°C. If B31.3 calls for impact test within this temperature.

Your feedback is very important to me.


Customer Care

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Aug 19, 2020, 12:09:11 AM8/19/20
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Dear Kiran,

 

It is rare that a low Cr-Mo alloy steel such as Group P5B is required to have an impact test at -29 C in its weld.

These steels are resistant to high temperatures of approximately 470 C to 650 C. So for what impact test? Structurally, for high temperature service a steel with a coarse grain size ASTM 4-5 (creep and oxidation resistant) is needed; and for low temperatures, tough steels with fine grain structure ASTM 8-9 are needed, which are suitable for cold service> -29 C to -45C.

 

The steels grouped in P5B are coarse-grained.

 

ASME B31.3 does not call for impact test at this temperature -29C. First of all, Kiran you must check the service temperature range of this pipe and its welding. What is approved in the Customer's specifications? I think your Customer  is wrong. Talk to him.

 

Regards,

 

Ramon Briceno/ Corrosion-Materials & Welding Engineer

 

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Paidi

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Aug 19, 2020, 12:28:53 AM8/19/20
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Well said... Exactly.. Coarse grained steel does not required Imoact test requirements unless until service is different than normal... Cryogenic and all 

To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/BL0PR03MB4243D86E83ED1D6C00059921AA5C0%40BL0PR03MB4243.namprd03.prod.outlook.com.

Raghuram Bathula

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Aug 19, 2020, 1:16:34 AM8/19/20
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Please go thro the previous discussions on the subject
These conditions are applied in particular where ambient temp is very cold, for e.g Russian region MDMT can go upto -50 deg c.


atul khatri

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Aug 19, 2020, 2:25:29 AM8/19/20
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As per  ASME B 31.3, LAS are exempted for impact test till -29 deg c  irrespective of thickness.

Regards
Atul Khatri

To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CAA%3D1_-xrRM5VdAO1EZe4LPiXQENTG0i0qv3d_ooFsqbGVW%3DM%2BA%40mail.gmail.com.

Customer Care

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Aug 19, 2020, 11:49:40 PM8/19/20
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Yes, it is understood, in an arctic environment like Russia, for example, the low temperature excursion is present in the services. But, if the process where the SA-335 P9 pipe is installed serves a furnace, boiler, reactor or incinerator operating in the creep and oxidation range; typically, the engineering specification indicates pipeline protection with traces of heating and thermal insulation that suppresses freezing.

Raghuram Bathula

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Aug 19, 2020, 11:58:26 PM8/19/20
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agreed, but need to consider startup/shutdown (or streams where continuous flow is not present) conditions also during design

pgos...@rogers.com

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Aug 23, 2020, 10:10:11 PM8/23/20
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Thermal cycling, frequent start up/ shutdown can play havoc, if the BM/Weld lacks proper impact strength. Hence it is a customary practice by many  design specifications to ask for impact test, even though the equipment is designed for elevated temperature service. Garde -91 steel is always used for service above 1100 F . ASME Code may  not mandate impact test, however clients’ specification, or industry standard, API RP 938B calls for impact. Asking  for impact test is an additional level of safety, at the discretion of the engineer during design/ construction.

 

Same is the approach for fabrication of Cr-Mo steels , conforming to API RP 934/A/B/C.

 

Thanks.

 

 

 

Pradip Goswami, P.Eng, IWE

Consultant-Welding-Metallurgical Engineering

Cell & Whatsapp-905-9793232.

Personal:pgos...@rogers.com

 

 

From: material...@googlegroups.com <material...@googlegroups.com> On Behalf Of Raghuram Bathula
Sent: August 19, 2020 11:57 PM
To: Materials-Welding <material...@googlegroups.com>
Subject: Re: [MW:31341] Re: Impact test requirements for LAS

 

agreed, but need to consider startup/shutdown (or streams where continuous flow is not present) conditions also during design

 

On Thu, 20 Aug 2020 at 09:19, Customer Care <bric...@hotmail.com> wrote:

Yes, it is understood, in an arctic environment like Russia, for example, the low temperature excursion is present in the services. But, if the process where the SA-335 P9 pipe is installed serves a furnace, boiler, reactor or incinerator operating in the creep and oxidation range; typically, the engineering specification indicates pipeline protection with traces of heating and thermal insulation that suppresses freezing.

 

Ramon Briceno/ Corrosion-Materials & Welding Engineer

 

Sent from Mail for Windows 10

 

From: Raghuram Bathula
Sent: Wednesday, August 19, 2020 1:16 AM
To: Materials-Welding
Subject: Re: [MW:31338] Re: Impact test requirements for LAS

 

Please go through the previous discussions on the subject

These conditions are applied in particular where ambient temp is very cold, for e.g. Russian region MDMT can go up to -50 deg c.

 


 

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