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