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