Guidance on DNV's DRILL notation

OFFSHORE TECHNICAL GUIDANCEAnnual Well control Complete periodicalSee “BOP stack*/ General”.BOP stack/ annularpreventer• Review initial certificate/ maintenance. History;• Visual survey:a) Disassemble for 100% visual inspectioninternally and externallyb) Verify markings to previous certificationc) Visually inspection of seals and packer/donutd) Visually inspection seal areas.• Non-destructive testing:a) MPI - all weldsb) MPI - bottom ring grooves, DPI if stainlesssteel inlayedc) MPI - all seal areas on body and other partsd) MPI – pistone) MPI - adapter ring/inner and outer cylinderheadsf) General hardness checks.• Dimensionally check:a) Bottom flange/hub thicknessb) Bottom ring groovesc) Through bored) Pistone) Adapter ring/ inner and outer cylinder heads.Note:The above dimensions to be verified to the originalmanufacturer’s dimensions and tolerances onthese. 3The maker’s dimensional information may often betried kept secret, but is often found available to therepair shops.• Pressure testing to maximum WP;• Weld repair (if required) see page 32.3 It is emphasized that DNV has no preference over OEM to non-OEM (see also section 4.1)DET NORSKE VERITASAppendix AOTG-07