Flanges

Weld neck flange attach to the pipe by welding the pipe to the neck of the pipe flange. The allows for the transfer of stress from the weld neck pipe flanges to the pipe itself. This also reduces high stress concentration at the base of the hub of the weld neck pipe flanges. Weld neck pipe flanges are often used for high pressure applications. The inside diameter of a weld neck pipe flange is machined to match the inside diameter of the pipe.

Slip-on flange actually slip over the pipe. These pipe flanges are typically machined with an inside diameter of the pipe flange slightly larger than the outside diameter of the pipe. This allows the flange to slide over the pipe but to still have a somewhat snug fit. Slip-on flanges are secured to the pipe with a fillet weld at the top and the bottom of the slip-on pipe flanges. These flanges are also further categorized as a ring or a hub Blind flange are pipe flanges used to seal the end of a piping system or pressure vessel openings to prevent flow. Blind flanges are commonly used for pressure testing the flow of liquid or gas through a pipe or vessel.

Blind flanges also allow easy access to the pipe in the event that work must be done inside the line. Blind flanges are often used for high pressure applications. Slip on Pipe flanges with a hub have published specifications that range from 1/2″ thru 96″.

Screwed flange are similar to slip-on pipe flanges except the bore of threaded pipe flange has tapered threads. Threaded pipe flanges are used with pipes that have external threads. The benefit of these pipe flanges is that it can be attached without welding. Threaded pipe flanges are often used for small diameter, high pressure requirements. Slip on Pipe flanges with a hub have published specifications that range from 1/2″ thru 24″.