Blind Pipe Flanges

Blind pipe flanges are carbon steel pipe flanges used to seal the end of a piping system or pressure vessel openings to prevent flow.

Blind pipe flanges are commonly used for pressure testing the flow of liquid or gas through a pipe or vessel. Blind pipe flanges also allow easy access to the pipe in the event that work must be done inside the line. Slip on Pipe flanges with a hub have published specifications that range from 1/2″ thru 96″. Coastal Flange provides Blind pipe flanges in all material grades, specifications and sizes.

Blind pipe flanges are typically provided with a raised face, flat face, or RTJ facing. When a raised face is necessary for blind pipe flanges, the standard height is 1/16″ for blind pipe flanges under 400#. For blind pipe flanges of 400# and up, the standard blind pipe flange raised face height is 1/4″.

Some important features of blind flanges are as follows:

• Blind flanges are sometimes supplied with NPT fittings which allow pressure test connections to be fitted.
• They are used to blank off the ends of structural steel pipe.
• They are also used to blank off the ends of valves and pressure vessel opening.
• Considering factors like internal pressure and bolt loading, blind flanges, especially in the larger sizes, are the most highly stressed of all types of flanges.
• Since the maximum stresses in a blind flange are bending stresses at the center, they can safely be allowed to be higher than in other types of flanges.
• Blind flanges are made to fit standard pipes in all sizes.