Flange Types
Threaded Flanges
Flanges with internal pipe threads for installation without welding.
Threaded flanges (also called screwed flanges) have a tapered NPT pipe thread machined into the bore per ASME B1.20.1. The pipe is simply screwed into the flange, eliminating the need for welding. This makes threaded flanges the preferred choice where welding is impractical, hazardous (explosive environments), or where the piping must be frequently assembled and disassembled.
Threaded flanges are manufactured in sizes from 1/2" through 4" and are most commonly used in Class 150 and Class 300 service. While they are available in higher pressure classes, the threaded connection becomes the weak point at elevated temperatures because differential thermal expansion can loosen the threads. For higher-pressure threaded applications, a seal weld at the hub-to-pipe junction adds security.
Flanges.IO stocks threaded flanges in carbon steel (A105), stainless steel (A182 F304/F316), and alloy materials. All threaded flanges conform to ASME B16.5 dimensional standards with NPT threads per B1.20.1. Contact us for availability and pricing on your threaded flange requirements.
