The electrical welding device adds material to {HEAD ~ the inside} of the valve body by using {TAIL ~ an electrode} to provide an arc 
The electrical welding device adds material to { HEAD ~ the inside } of the valve body by using { TAIL ~ an electrode } to provide an arc
OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH