Socket Weld Procedure for 5-Inch Pipe

How do you weld the inside ?

First pipe to collar, I understand but the second pipe is silipped into the collar, now you can only weld on the outside isn't it ?

The other procedure is for strengthening collar when you butt weld the pipes together and then slip on the collar over the joint and fillet weld. But here you want a gap of 1.6mm between the pipe ends so that is also ruled out.

Why don't you ask the customer for weld details ? he is supposed to provide it.

In some cases you can not get the inside joint. ( cap, etc ) But when ever possible you should run a root pass at minimum to the inside joint, (example an Flange).

On socket weld collar (coupling) you will only weld the outside fillet weld. The small gap is put in there for expansion between the pipe end and the inside of the collar. I would suggest you use SMAW with E-7018 low hydrogen electrode if the material is mild steel such as SA-106 B or a 53 pipe and SA-105 coupling. If your pipe is of some other alloy then use the appropriate matching filler metal (electrode). You can also use GTAW with a ER 70S2 rod but this would be very large piece to use GTAW in my Opinion.

First and foremost is what code are you mandated to follow, is this for an LNG plant or a water house line for a customer,(big difference). After you have established the code, (AWS, API, ASME...) you will need to know what materials are to be welded and what filler metals are designed for welding the materials, this information is critical/essential to every weld procedure.

Protect others, yourself and your company, always follow the appropriate code and use a qualified weld procedure and qualified welder.

F.Y.I.-One of the most common mistakes is overwelding of the fillet weld.

As a indutrial heater/furnace manufacturer, a year or two ago I was asked to quote and build a number of heater flanges and vessels. I asked a boiler manufacturer "friend" whether my design needed to be certified as a pressure vessel. The answer was no, HOWEVER he was wrong.

It cost me ZAR15K; 1650 USD to have an engineer do "design calculations" and then another ZAR15K; 1650 USD to have an independent Third Party Inspector come and do NDE testing (radiography, Magnetic particle etc etc) on my welds for the 4 vessels I built. Never mind the costs of having my welder "coded" to do the various types of welds required. The drawings were stamped "approved" and so were all my documents including material certificates certified, the vessels registered, the welders qualifications, the weld procedure, et al et al. At the end of the day, the job and supporting documents made my work look 100% better than anybody else's.

I paid my "school fees" and learnt the hard way, get the design idea to engineers first and ask them whether or not it needs to be certified and what type of weld procedures need to be followed.

And yes my boiler friend is still a friend and client-however I do charge him a bit more than I used to for spares.