• (#22) is a section of large diameter pipe fitted to the top of the that the attaches to via a side outlet, to allow the to flow back to the .• (BOPs) (#23 and #24) are devices installed at the wellhead to prevent fluids and gases from unintentionally escaping from the . #23 is the annular (often referred to as Hydril named after a manufacturer), and #24 is the pipe rams and blind rams.
[pdf] DSSV, FOSV & IBOP Valves are used to control fluid through the ID of wellbore tubulars. These valves have been the choice of well drilling and workover companies for more than 30 years.
[pdf] 
