The socket weld flange
is generally applied on pipes with smaller sizes but high pressure. These pipe flanges are attached by inserting the pipe into the socket end and applying fillet weld around the top. This allows for a smooth bore and better flow of the fluid or gas inside of the pipe. Slip on Pipe flanges with a hub has published specifications that range from 1/2 inch to 24 inch.
Socket Weld pipe flanges are typically provided with a raised face, flat face, or RTJ facing. When a raised face is necessary for socket weld pipe flanges, the standard height is 1/16 inch for socket weld pipe flanges less than 400#. For socket weld pipe flanges of 400# and up, the standard socket weld pipe flange raised face height is 1/4 inch.