GROCO 1-1/2" Bronze NPS to NPT Flange Adapter [IBVF-1500]1 1 2" Bronze NPS to NPT Flange Adapter IBVF Flanged Adapters have been developed to address several common problems in the marine industry. Features: Eliminate dangerous thread miss match when in line valves are screwed onto thru hulls Accept standard thru hulls into the base and standard in line valves on top Provide a safe and sturdy assembly when in line valves are used as seacocks For OEMs, prevent valve damage during engine or generator