GROCO Seacock Backing Blocks

Create a secure seacock installation with these rigid backing blocks.

Flanged seacock installations improve with the use of a backing block between the valve flange and the hull. Each backing block size fits multiple seacock sizes. Backing blocks include threaded inserts that press into the hull side of each block, into the holes that match the seacock flange. The 1/2″ thickness is rigid enough for a secure installation, but flexible enough to conform to minor hull curvature. Backing blocks will not absorb moisture.

NOTE: Seacock shown for illustration only (sold separately).

Key Features

• Each size fits multiple seacock sizes 
• Threaded inserts included to match the holes in the seacock flange
• Rigid 1/2″ thickness 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

Model	Accepts Seacock Size	Diameter	Threaded Inserts
15939267	3/4″ & 1″	4 9/16″	5/16″-18
15939275	1 1/4″ & 1 1/2″	5 3/8″	5/16″-18
15939283	2″ & 2 1/2″	7 1/4″	3/8″-16
15939291	3″ & 4″	9 1/2″	1/2″-13