Azedine This question of Socket weld fit up to contraction ring joint gap has to be answered and looked from practical fabrication difficulties and also from existing code practices: ASME Sec I Para 41.5.2 gives the minimum gap as 1/4". ASA B 31.1 1998 127.3 (Preparation for welding for Socket Welding (E) gives the gap between the contraction ring fit up and the socket weld as 1/16" gap ( approx. 2 mm) i.e., you allow a known gap of 2 mm for contraction between the edge of pipe and socket weld. UK code practice - though had not specified exactly the minimum gap suggests an expansion gap of 2 mm and if needed Radiography of the socket weld to contraction ring joint after welding. Question always arises : How to exactly measure a 1/16" gap in such joint configuration of a pipe edge and socket weld. I guess it is safer to think of a 2 mm expansion gap - which UK code practice and ASA 31.1 insists / suggests. ASME Sec 1 gives more allowance of 6 mm which may not be needed. If structural integrity and joint strength is required more, 2 mm will pose some limitation in welding unless TIG process with 1.6 mm filler wire is used. With a SMW process and normal fabrication proactice of using a 1/8" elecrode will give problems of improper fusion which has to be confirmed by RT only. Surprisingly ASME Sec VIII Div 1 /2 does not mention clearly about this. Trust this clarfies your question. C.V.Srinivasan Nishi Engineers Pvt Ltd India Mar 04,2007 E-mail: nishi@vsnl.com >DEAR, > >I would like to have some informations about the Gap.A.let >socket weld contraction rings to respect the gap between the >pipe end and the internal shoulder of the fitting before >welding. >Yours coimments will be appreciated. > >Best regards >Azedine