Groco Backing Blocks – Flanged Seacocks

Flanged seacock installation is improved with the use of a backing block between the valve flange and the hull. The common practice of making “homemade” backing blocks can be cumbersome and when done incorrectly can lead to weaker valve assemblies. The BB Series Backing Block is designed to take the guess work out and to make that installation as simple and hassle free as possible.

Each size fits multiple seacock sizes.
Press threaded brass inserts into the hull side of the backing block into the holes that match the seacock flange.
Rigid 1/2″ thickness provides secure installation but is flexible enough to conform to minor hull curvature.
Will not swell or absorb moisture.
Made from an environmentally friendly PVC foam specially formulated for marine applications.