GROCO 3/4-Inch Bronze NPS/NPT Flange Adapter

The GROCO IBVF-750 flange adapter is designed to create a safer transition between a standard thru-hull and an in-line valve used as a seacock. The thru-hull enters the base of the adapter, while a compatible in-line valve attaches above it. It addresses the thread mismatch that can occur when tapered pipe-thread valves are screwed directly onto straight-thread thru-hulls. That arrangement gives the valve a stable flange-style foundation without requiring a dedicated seacock body.

For OEM installations, the flange adapter can be mounted first and the valve added later, reducing the chance of damaging the valve while engines or generators are being installed nearby. GROCO developed the IBVF family to make new installations and future valve replacement easier. This version is cast for marine use and is intended to become part of a properly supported hull-side plumbing assembly. The adapter also gives a replacement valve a standardized connection point, so future service does not require disturbing the thru-hull itself.

• Allows the valve to be installed or replaced separately
• Creates a proper transition between thru-hull and in-line valve
• Helps eliminate straight/tapered thread mismatch
• Provides a stable flange-style seacock foundation

Dry-fit the IBVF-750 with both the thru-hull and intended valve before final bedding so thread engagement, handle clearance, and hose direction can be confirmed. Use backing and fasteners appropriate to the hull construction, and support the connected plumbing independently of the adapter. After installation, exercise the valve and inspect every joint for leakage before returning the system to normal use. For other adapters, service fittings, and plumbing-control components, browse Marine Pipe Fittings.