Trumbull Sealed Floor Boxes are ideal to prevent fluids or vapors from penetrating the floor slab from either direction. Top side is sealed by a Buna-N O-ring, and bottom side can be sealed by use of optional packing gland. Overall length is 6”, but the underside is tapped to accept 2-1/2” NPT steel pipe nipples. When it’s necessary to convert a Floor Box to thicker floors, use a 2-1/2” pipe nipple, 1/2” longer than the increase required, as the threads on the underside of the Floor Box are 1/2” deep.

NOT for use with Valve Position Indicators. Click THIS LINK for Sealed Floor Boxes that can accommodate them.

Tapped 2-1/2″ threads also permit threading 2-1/2″ pipe into underside of Floor Box, to provide an external casing for a smaller internal extension stem.