NPT (National Pipe Thread) is a widely used tapered mechanical interface in electrical feedthroughs, valued for its simplicity, low cost, and ease of installation. Sealing is achieved by tightening threaded fittings with tape or sealant, creating a pressure-tight interface. Compared to SAE threads, which use parallel threads and O-ring or metal cone seals, NPT offers a more straightforward solution, though with some limitations in critical sealing and pressure performance.

Douglas Electrical Components manufactures hermetic NPT feedthroughs for vacuum, positive pressure, and hazardous environments. Using epoxy sealing technology, these feedthroughs allow wires, cables, connectors, or optical fibers to pass through bulkheads while preventing the transfer of liquids and gases. In hazardous locations, they help block flammable substances from reaching ignition sources, supporting explosion-proof system designs.

A variety of NPT feedthrough types are available, including wire feedthroughs (wire bushings or conduit seals), connectorized feedthroughs, terminal seals for power transmission, and thermocouple feedthroughs for temperature sensing. Designs can be customized with different materials such as stainless steel, brass, aluminum, or high-strength nickel alloys, which influence pressure ratings and corrosion resistance. Common sizes like ½” NPT are widely used due to their compact form and compatibility with standard conduit systems.

Douglas also offers explosion-proof NPT feedthroughs certified to standards such as UL1203, with options for hazardous area classifications and compliance with IEC and ATEX requirements. While NPT feedthroughs are cost-effective and versatile, they are best suited for applications where ease of use and moderate sealing performance are prioritized over extreme pressure or critical sealing demands.