FLANGES 

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. (Customer 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.

Orifice Flanges are intended for use instead of standard pipe flanges when an orifice plate or flow nozzle must be installed. Pairs of pressure "Tappings", mostly on 2 sides, directly opposite each other, are machined into the orifice flange. This makes separate orifice carriers or tappings in the pipe wall unnecessary. On the image above a set Orifice Flanges is shown, where the tappings are sealed with a plug, and where a jack screw is machined. This jack screw is used to facilitate separating the flanges for inspection or replacement of the "Orifice Plate.

Ring joint flange is a special type of flange connection in which a metal ring (resting in a groove in the flange), ring joint flange manufacturers, serves as a pressure seal between the two flanges. RTJ flanges seal when tightened bolts compress the gasket between the flanges into the grooves, deforming (or "Coining") the gasket to make Intimate Contact inside the grooves, creating a metal to metal seal.