We provides ASME Code and Non Code Industrial flanges for the Petrochemical, Process, & Waterworks industries. ANSI, API, AWWA pipe flanges in carbon, stainless, alloys and chrome steel. Weld Neck flanges, Slip on flanges, Blind flanges, Threaded flanges, socket weld flanges, Lap Joint flanges, Orifice Flanges in sizes 1/2" to 198".
Blind flanges are generally used to blank off the ends of pipe. They are also used on similar valves and pressure vessel openings. Because they are often located at the ends of systems, these flanges often are among the highest stressed flange types. However, most of these stresses are bending types near the center, and since there is no standard inside diameter, these flanges are suitable for higher pressure temperature applications.
Lap Joint Flanges are used with a corresponding stub-end that "inserts" in the inside of the flange. The main benefit of this type of flange, is that once the pipe welds to the insert stub-end, the flange then can rotate for easier alignment of the bolting holes. However, lap joint flanges and their stub-ends' ability to hold pressure is about the same as slip-on flanges. They are not suitable for situations with a high external or changing loads of force. They do provide an advantage in a piping system that needs frequent dismantling for inspection or to remove build-ups. If high pressure applications are being performed, either a swivel ring flange or an insert flange, is recommended to be used instead of a lap joint flange an stub-end.
Orifice Flanges are used with orifice meters for the purpose of measuring the flow rate of either liquids or gases in the respective pipeline. Orifice flanges generally come with either raised faces or RTJ (Ring Type Joint) facings. They are, for all intensive purposes, the same as weld neck and slip-on flanges with extra machining. They have modifications of radial tapped holes in the flange ring for meter connections and orifice plate carriers for the reason of fitting meter connections. The additional bolts act as a jack to allow the separation of the two flanges to change the orifice plate or for other inspection services.
Slip-On Flanges are probably the most common type of flanges in the industry and are ideal for lower pressure applications. You do not have to specify the pipe schedule when using slip-on flanges due to the fact that its inside diameter is determined by the outside diameter of the pipe. This outside diameter of the pipe does not change for the different schedules. This often makes these easier to stock for vendors. Fabricators also like the fact that these flanges are slightly easier to align than weld neck flanges. They also are slightly easier to cut pipe to the proper length for. They can be used for high temperature and pressure applications but are not generally recommended as compared to other types of flanges. ASME B16.5 Code limits their usage in the 1500#-2500# (lbs.) weight classes. (download the cut sheets in the right margin) The three most common types of facings that SFF carries for slip-on flanges are raised face (most common), flat face, and ring type joint (RTJ).
Weld Neck Flanges have a long tapered hub and are often used for high pressure applications. The three most common types of facings that Specialty Flange and Fitting, Inc. carries for weld neck flanges are raised face (most common), flat face, and ring type joint (RTJ). When ordering a weld neck flange, it is important to specify the schedule pipe is being used for. This is because the inside diameter of the flange will match the inside diameter of your pipe. The buttweld joint this flange has with the pipe along with the tapered hub, makes this flange very resistant to dishing and a very sturdy connection. These flanges are ideal for extreme fluctuations of temperature and in environments where there may be a lot of bending and handling of the flanges.