Tubing head spool:Adapter Spools, Spacer Spools, Drilling Spools, Riser and Diverter Spools in accordance with API 16A Tubing head spool ... Tubing head spool :Adapter Spools, Spacer Spools, Drilling Spools, Riser and Diverter Spools Ruiyi manufactured are all in accordance with API ... :2 1/16”-4 1/16”Temperature class: K,L,P,R,S,T,UPerformance class:PR1,PR2Production class: PSL1,PSL2,PSL3,