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.

Floor Boxes

Material Trumbull Item No. Weight
Cast Carbon Steel* 367-4623 24.20 lbs.
Cast 316 Stainless Steel 367-4624 23.50 lbs.
* Carbon steel models are EDP coated.


BRASS BUSHING aligns extension stem when bottom seal is not utilized.

PACKING GLAND with stainless steel follower seals bottom of Floor Box.

Description Trumbull Item No. Weight
SS Packing Gland spec/ord 2.10 lbs.
Brass Bushing spec/ord 1.75 lbs.