Thanks & Regards
J.Gerald Jayakumar
Dear Sir,
Thank you so much for your sincere response. We are worried about no flow in the pipe because isolated by check valves on both sides. Another worry the client doubt about valve may have passing so.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/1306834709.879538.1615356024823%40mail.yahoo.com.
--
Hi,
Hot tap is very frequently applied on pipelines and piping carrying hydrocarbons. Hydrocarbons are flammable, explosive. Traces of hydrocarbons can easily introduce flames and fires. Hence safe operating procedures, knowledge base of personnel frequently doing this work are important. You need to check with your operations personnel on the best and safest way for hot tapping.
API 2201 provides exhaustive information on Hot Tapping. In fact, its’ the industry document for his technique of “in situ alterations/ modifications in pipelines. There’re many checklists, points to be considered for safe hot tapping work. I’ve attached some extracts and highlighted texts from this document.
It’s advisable to avoid any flow of gases/ hydrocarbons during hot tapping.
I hope the attached information would be of help.
Thanks.
Pradip Goswami.P.Eng, IWE.
Independent & Consulting Welding & Metallurgical Engineering Specialist
Saudi Aramco Approved Designated Welding Engineer(DPWR)
Linkedin: https://www.linkedin.com/in/pradip-goswami-2999855/
Email:pgos...@rogers.com,pradip....@gmail.com
Cell/Whasapp:1-905-9793232
From: material...@googlegroups.com <material...@googlegroups.com> On Behalf Of Venkatachalam Govindan
Sent: March 9, 2021 8:18 AM
To: material...@googlegroups.com
Subject: [MW:32036] In -service welding on HP Gas line, prior to Hot Tapping. Need immediate suggestions.
Dear Respected ones,
We are planning a hot tapping on the HP gas line, which is 30" dia, and thickness 15mm, and carbon steel material.
Around 15-meter length, where both the ends are closed by check valves.
The line is isolated, we want to weld a 2" dia ventilate on the 30" pipe.
There is no flow is possible. We have to complete this work at any cost, the client says. Is this okay for you? it can be safe? – You need to have a check of any remaining gases, vapor, with Tracers
Due to 15mm thickness, we are planning to do by 2.5mm, E 7018 electrode by the lower current.
Please advise, any vapor cloud will be an issue inside the pipe? or we can do it because thick ness is high? or shall we ask for at least a minimum flow so the vapor cloud will not be there.
Looking sincerely your support friends.
For your information, we regularly do such hot tapping works, at 800PSI pressure, but, with the flow. 04m/s.
--
Venkatachalam Govindan
QHSE Lead | Auditor | Trainer
(API U Trainer | IRCA Lead Auditor | Exemplar Global MS Specialist |CQI Practitioner)
Mobile +965-97604989
--
https://materials-welding.blogspot.com/
https://www.linkedin.com/groups/122787
---
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-weld...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CAHOK3OfUZGZA2VWW32o3GzHM4Z19ZcGXiOSpz4G%2BrgbvrtgxVQ%40mail.gmail.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CAH5TVhasyAEcOUniDtcKqKAk0Nqo9Cu3DyO%2BJwwRsFJxeLeqQA%40mail.gmail.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/BN8PR20MB241927BE5FCD48B15D22DCC3AA909%40BN8PR20MB2419.namprd20.prod.outlook.com.
Thanks & Regards
J.Gerald Jayakumar
Hi,As you have mentioned in your email already , it is always recommended to carry out Hot-TAP welding with a certain amount of minimum flow.In this case, the run pipe thickness is 15 mm. So,the risk is really low. Just recently, we qualified a HOT-PQR with 7.9 mm thickness and while buttering pass the maximum inside temperature on run pipe found is 350 Deg C .I suggest you the following ,Discuss with the process safety engineering team and seek advise on the maximum allowable inside temperature that is acceptable while welding(1st pass I.e buttering and 2nd pass mainly)They ll advise based on flash and fire point and internal pressure built up due to gas expansion and so on.Also, check the feasibility for nitrogen purging the line during welding.Regards,Sudhakar K
--
https://materials-welding.blogspot.com/
https://www.linkedin.com/groups/122787
---
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-weld...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CAHOK3OfUZGZA2VWW32o3GzHM4Z19ZcGXiOSpz4G%2BrgbvrtgxVQ%40mail.gmail.com.
--
--
https://materials-welding.blogspot.com/
https://www.linkedin.com/groups/122787
---
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-weld...@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CAHOK3OfUZGZA2VWW32o3GzHM4Z19ZcGXiOSpz4G%2BrgbvrtgxVQ%40mail.gmail.com.
Yes, we doing nitrogen purging. Thanks for your details with the experiment.Best Regards,Venkat G
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CABF8NYUL2GvimavHc4-XzfHkRW%2B0Vx%2BzRzbeXL8Py1ipb-TUyw%40mail.gmail.com.
----
Venkatachalam Govindan
(IRCA Certified Lead Auditor & API / CQI Practitioner)
+965 - 97604989 / +965 - 99798437
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/824951860.93338.1615544357733%40mail.yahoo.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CABF8NYUL2GvimavHc4-XzfHkRW%2B0Vx%2BzRzbeXL8Py1ipb-TUyw%40mail.gmail.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CAHOK3Od2iRDkeQuTNpg5d-w0gT1d0V1PadXZex91S%2Bx6zGhXUA%40mail.gmail.com.
--
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CABF8NYUK5aXkKXLMScbAyTxDioy%3D%3DCDocHric9Y6GcJtNp7fDA%40mail.gmail.com.