Specialty Flange & Fitting, Inc.
649 Lebanon Avenue
Williamstown, NJ 08094
Phone: (856) 728-8530
Fax: (856) 728-1304
"Specializing in Stainless Steel & Alloy
Pipe, Valves, and Fittings for 25 years.

Blind Flange   Lap Joint Flange    Orifice Flange   Slip-On Flange
Socket Weld Flange
    Threaded Flange    Weld Neck Flange

Socket Weld Flange 

Socket Weld Flanges are similar to slip-on flanges, however, socket welds have an internal recess on the inside diameter to allow for a smoother flow of the process fluid.  The positive of this is that is creates a smooth bore with the proper welding and grinding.  The negative of this type of flange is that it can be more expensive than a slip-on due to more intricate machining, and they can be less readily available than slip-ons due to the fact that the bottom half of the inside diameter must be made to the same schedule as the pipe that is being used. (you must specify the schedule needed)  These socket weld flanges were initially developed for use on smaller sizes of pipe at higher pressure ratings.  They are more used on lower pressure temperature as well today.  Specialty Flange and Fitting, Inc. offers these flanges in stainless and alloy material.  See the diagram below for the general place the pipe fits in the flange.

Key Features:

  • The recess on the inside diameter allows for a good fit of the pipe allowing for a smooth flow of liquid
  • Work well for smaller sizes and higher pressure temperature conditions.
  • Similar to slip-on flanges, but must specify the pipe schedule they will be used for with socket welds

The below diagram shows the inside diameter of a socket weld flange.  This flange happens to be what is known as an insert flange.  It is a two-piece flange allowing for rotation of the outer flange for easy alignment of bolt holes.  SFF can supply these flanges along with standard one-piece socket weld flanges.
Socket Weld Insert Flange