... gas wellhead consisits of threaded flange,gate valve,studded cross ,adapter spoolNB:2-9/16" 3-1/16" etc wellhead xmas ... casing head, casing spool,tubing spool,tubing head adapter,studded cross, threaded flanges,adapter spool,gate valve,choke valve and the tree ... gas wellhead consisits of threaded flange,gate valve,studded cross ,adapter spool