The type of flange used for a piping application usually depends on the required strength for the flanged joint. Flanges are used to weld connections. In addition, it helps to facilitate maintenance operations.
Let’s dive in to show the key types of flanges with pictures.
Welding neck flange
A welding neck flange features a long tapered hub that helps weld the pipe. The flange type is normally used in high/low temperatures and high-pressure applications requiring unrestricted flow if the piping system conveys the fluid.
The absence of pressure drops prevents the adverse effects of erosion/corrosion and turbulence of the metals in the flanged joint proximity.
Long welding neck
Long weld neck flanges are quite similar to weld neck flanges. However, it comes with the exception that the neck is extended and acts like a boring extension.
Long weld neck flanges are usually used on barrels, columns, or vessels.
You can connect the slip-on flange to the pipe or the fittings by the two fillet welds, one outside and one executed inside the flange cavity.
The bore size of the slip-on flange is large than the outside diameter for pipe connection, as the pipe has to slide inside the flange that you can connect by the execution of the fillet weld.
Threaded flanges are joined to the pipes by screwing the pipe onto the flange without the seam welds. Threaded flanges are available in sizes for up to four inches and multiple pressure ratings; however, they are used mostly in low-temperature applications and small-size piping in low-pressure-like air and water utility services.
Socket weld flange
You can connect socket weld flanges to pipes with the use of a single fillet weld executed on the outer flange side.
As per the ASME B31.1, to execute the flanged connection with a socket weld, the pipe must first insert the flange’s socket until it reaches the bottom of the flange. It then needs to be lifted by 1.6 mm and welded finally.
Lap joint flange
The lap joint flange features a flat face and is always useful in conjunction with the stub end. Lap joint flanges usually resemble the shape of slip-on flanges, except for the radius at the flange face crossing and the bore to accommodate the flanged portion of the stub end.
When we talk about the lap joint flange, it can slip over the pipe and seats on the back of the stub end, and you can keep the two together by the pressure of the bolts.
Contrary to all the flange types above, blind flanges do not have a center hole. Therefore, you can use the seal or blind in a pipeline or a pressure/valve vessel to block the fluid of the liquid.
Blind flanges need to withstand remarkable mechanical stress due to the system pressure and required bolting forces.
You can easily access the blind flanges to the pipeline, as they can be easily unbolted to let the operator execute the activities while inside the terminal end of the pipe.
Interestingly, while this flange type is easy to manufacture, it is sold at the average premium cost per kg compared to the other flange types.
Special types of flanges
The special types of flanges include:
3. Latroflange or Elboflange
4. Swivel flange
5. Expanding flange
6. Reducing flange
The flanges mentioned above are usually the top flanges available to us. However, you can get in touch with Texas flange if you are looking for top-quality flanges. You can also contact us for any queries regarding the flange function.