... , and thread type. Christmas tree is an important piece of equipment used to control fluid flowing. Specification:The bore of casing head ... level of our product being PR1, PR2, under API SPEC 6A.The bore of Christmas tree ranges from 7-1/16 to 21-1 ... HH, the manufacturing level being PSL1, PSL2, PSL3, the performance level of our product being PR1, PR2, under API SPEC 6A. wellhead and christmas tree