Electrically isolating block and flange for rail-heating duct
An electrically isolating duct-connecting block for connecting two ducts, the duct-connecting block including a rigid, generally rectangular duct-like structure having upper and lower walls and side walls that match a cross-sectional size of a tie duct, the structure being made of an electrically nonconductive material. The block also includes a plurality of threaded fasteners embedded within the structure. Also disclosed is an electrically isolating nozzle-mounting block for mounting a nozzle to a tie duct, the nozzle-mounting block comprising a rigid flange-like structure having peripheral mounting holes and a central circular passage for conveying air to the nozzle, the structure being made of an electrically nonconductive material. The block also includes a plurality of threaded fasteners partially embedded within the structure. The blocks may be made of ultrahigh molecular weight polyethylene or any electrically and mechanically equivalent material.
1. An electrically isolating duct-connecting block for connecting two ducts, the duct-connecting block comprising:
a generally rectangular rigid duct-like structure having upper and lower walls and side walls that substantially match a cross-sectional size of the ducts, the structure being made of an electrically nonconductive material; and
a plurality of threaded fasteners partially embedded within the structure, each of the plurality of threaded fasteners having a head, the head of each of the plurality of threaded fasteners electrically isolated by a dielectric sealant, each of the plurality of threaded fasteners having a threaded portion, a first threaded portion of a first threaded fastener of the plurality of threaded fasteners extending in a first direction, a second threaded portion of a second threaded fastener of the plurality of threaded fasteners extending in a second direction opposite the first direction.
2. The duct-connecting block of claim 1 wherein the head of the each of the plurality of threaded fasteners are electrically isolated by an epoxy sealant.
3. The duct-connecting block of claim 1 wherein the structure is made of ultrahigh molecular weight (UHMW) polyethylene.