Groco BB-Series Backing Block

Features:

• Flanged seacock installation is improved with the use of a backing block between the valve flange and the hull
• Each size fits multiple seacock sizes
• Press threaded inserts into the hull side of the backing block into the holes that match the seacock flange
• 1/2" thickness is rigid enough for a secure installation but flexible enough to conform to minor hull curvature
• Will not swell or absorb moisture
• Applications: 1-1/4" and 1-1/2" Seacocks
• Diameter: 5.38"
• Threaded Inserts: 5/16"-18