This trough is then deepened by extending {TAIL ~ its inner wall} in {HEAD ~ upward direction}, and the thus formed deeper trough is then filled with welding material, preferably up to the top surface of the pressure conveying element 
This trough is then deepened by extending { TAIL ~ its inner wall } in { HEAD ~ upward direction } , and the thus formed deeper trough is then filled with welding material , preferably up to the top surface of the pressure conveying element
OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH