... , simple construction 4.Compact body saves space Spherical blowout preventers (API 16A series) Working path ( mm ) 180,230,280,346,426 ... of L, P, R, S, T, UProduct specification level PSL1, PSL2, PSL3Product performance level PR1, PR2Working medium can be hydrogen sulfide ... without drilling tool, can fully closed wellhead. Spherical Blowout Preventers (API 16A series)