Materials & Welding

Dear Asad Azmi, My Point wise Reply for your Query is as follows - The Thickness of your vessels is within the requirements of UG-84(6mm or 25% of the thickness) - Practically I think the welding of these three vessels will not be possible within three month span for all 'A' & 'B' Catagory Joints, if your production schedule is possible you can go for lesser number of PTC. - Eraction at Single site has no advantage the fabrication should be done at same location for three vessels. - As the heat number is not same but material specification is same you can choose the material from any one heat. - The Seperate PTC requirement will not be due to Long(A) & Circ Seam(B). The difference will be as per Position and Procedure. - I assume you will use two procedure one of SMAW & other of SAW welding. Final Solution: 1. Select the material of PTC of 70mm thick from any heat, Weld the same with SMAW in 3G Position it will cover all the positions ( i.e Long & Circ ...

Dear Majdi,   You didn't mention the material designation(pipe and split tee material) and thickness of the pipe/split tee material.If you could provide it,it will be easy for experts to analyse your query.I also have interest in this matter.     Regards,   Limesh On Sun, Nov 28, 2010 at 6:45 PM, Majdi N Elyyan < melyyan@gmail.com > wrote: Dear All;   We have a hot tap on LPG line (Sour service) which require PWHT. The run Pipe is 4", the branch is also 4", split tee will be used. As per shell DEP-31.38.60.10 – for Hot tapping, clearly mention: Hot-tap welding should not normally be performed on materials which require post-weld heat treatment. However, if stress relieving or post-weld heat treatment is required, a specialist shall be consulted to assess whether it is feasible to make the specific hot-tapping operation with post-weld heat treatment. Note: Stress-relieving may be required if a material is susceptible to stress corrosion crackin...

see here weldment is and HAZ is not coming in contact with process fluid.    two buttweld you can weld with back strip in place,    two fillet weld, as  we weld support where we are not performing any PWHT.   regards   manoj On Sun, Nov 28, 2010 at 6:45 PM, Majdi N Elyyan < melyyan@gmail.com > wrote: Dear All;   We have a hot tap on LPG line (Sour service) which require PWHT. The run Pipe is 4", the branch is also 4", split tee will be used. As per shell DEP-31.38.60.10 – for Hot tapping, clearly mention: Hot-tap welding should not normally be performed on materials which require post-weld heat treatment. However, if stress relieving or post-weld heat treatment is required, a specialist shall be consulted to assess whether it is feasible to make the specific hot-tapping operation with post-weld heat treatment. Note: Stress-relieving may be required if a material is susceptible to stress corrosion cracking and post-weld heat treatment may be speci...

Dear friends, we had a case recently where wleders were grinding too much after first pass, so we had some cracks and it was hard to find the reason for them...   Ing. Luis Albanés M.   El Salvador cel 503 70488959 Skype: albanes61 fax 1 303 479 6738 http://www.wix.com/LuisAlbanes/Luis_Albanes www.youtube.com/Cuyanausul   --- El sáb 27-nov-10, César Alexis Viteri Pérez <alexis_viteri@hotmail.com> escribió: De: César Alexis Viteri Pérez <alexis_viteri@hotmail.com> Asunto: RE: [MW:8410] Cracks in pipe wedling A: materials-welding@googlegroups.com Fecha: sábado, 27 de noviembre de 2010, 10:22 Dear C.Nagabhushanam   Please find attached a WPS for a similar welding. According to my experience for heavy pipes, preheat , clamping time  and time between passes can generate cracks, for instance during 4 first passes has not to be any movement of pipeline and time between them has to be short. Let a joint only with three or ...

Dear Mr.Asad Azmi, 1. For each vessel, one test plate shall be made for each welding procedure used for joints of Categories A and B. ( If u use same process for A & B category, one PTC is sufficient). 2. If u consider the group of vessel, then the following have to be satisfied to avoid multiple PTC. (below is from UG-84(i)3(b)) For several vessels or parts of vessels, welded within any 3 month period at one location, the plate thickness of which does not vary by more than 1⁄4 in. (6 mm),or 25%, whichever is greater, and of the same specification and grade of material, a test plate shall be made for each 400 ft (120 m) of joints welded by the same procedure. (if u go by this option, a seprate log to be maintained for day to day welding activities including each welder productivity, consumables consumption.) 3. The vessel impact test plate shall be from one of the heats of steel used for the vessel or group of vessels. Regards P.Yoganandhan On Fri, Nov 26, 2010 at 3:00 PM, asad ...

Dear All;   We have a hot tap on LPG line (Sour service) which require PWHT. The run Pipe is 4”, the branch is also 4”, split tee will be used. As per shell DEP-31.38.60.10 – for Hot tapping, clearly mention: Hot-tap welding should not normally be performed on materials which require post-weld heat treatment. However, if stress relieving or post-weld heat treatment is required, a specialist shall be consulted to assess whether it is feasible to make the specific hot-tapping operation with post-weld heat treatment. Note: Stress-relieving may be required if a material is susceptible to stress corrosion cracking and post-weld heat treatment may be specified by the design code if the wall thickness is greater than a certain limit.   & since we have no other options, we have to do the hot tap on the same, kindly advice WPS & PWHT procedures   Thank all in advance..   Regards Majdi Elyyan

316 is material grade, not standard. Based on end application, product form standard will be separate. For example, ASTM A666-Specification for stainless steel sheets which includes 316. ASME SA 240-Specification for SS plates, ASME SA312-Specification for SS Pipes. 2010/11/27 Srinivas Engr < srinivas.gmsrini@gmail.com > Dear all If i search in google, it ASTM 316 is a SS plate & bars. But in ASME there is no such material grade........ Pl clear me.... Rgds Srinivas -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents. -- regards, Harish. -- To post to this g...