A customer is asking me to design a nozzle welding to a forged valve body.The thickness T1 of the valve body is large overdesigned.OD2 and T2 (see attachment) are NPS & SCHEDULE of a standard pipe, and the schedule is the same of the main valve (Valve 12" #2500 SCH.160 -> Nozzle NPS 1" SCH.160).How can I suppose that I don't need any reinforcement and how can I verify the wall thickness of the nozzle pipe. I think that I don't need any reinforcement due to the big valve thickness, but I'm not sure.ASME VIII gives a formula to calculate T2 for this design condition?You can either treat this as suggested by you, as a pure mechanical problem. This can be solved either by calculation (Contact the original factory? Heating alterations of material by welding controlled?), or by the old and simple 'this seems to be more than solid enough' methode.The other way is to search for the 'why' behind this solution, and search for alternatives : valves already constructed more suitable for the purpose, or nipple shifted to the pipework itself in stead of the valve, or already other existing process equipment, layout or other ways to solve the problem.If this is a critical service all sorts of tests, certifications and guarantees may be required for the valve after the welding. Is this required here? Who's going to pay for eventual damages by failure?Normally such extra additions to original equipment is suggested to save mony on buying new or other proper equipment.The question is always if mechanical alterations on original equipment is acceptable against a possibly increased risk of failure. If the answer is yes, you can safely go on with your added nipple.

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