What are the Flanges?
To build a piping system, flanges connect valves, pipes, pumps, and other parts of pipework. Flanges are frequently welded or threaded. There and two flanges are bolted together with gaskets to provide a seal that allows for easy access to the pipe system. Flanges include slip-on flanges, weld neck flanges, blind flanges, and socket weld flanges, to name a few. The various types of flanges used in plumbing systems are listed here, along with their diameters and other characteristics.
Types of Flanges
Blind Flanges
Stainless Steel 316 Blind Flanges are used to blank off the ends of pipes, valves, and pressure vessel openings because they are made without a bore. Blind flanges, especially in larger sizes. They are the most overstressed flange types in terms of internal pressure and bolt loading. Nonetheless, the majority of these pressures are around the center bending kinds, and because there is no defined inner diameter.
These flanges are appropriate for greater pressure-temperature systems. These flanges’ purpose is to block a section of pipe or a nozzle on a vessel that isn’t in use. For pressure checks in a factory or simply because the customer does not require all of the nozzles, the nozzle is frequently blanked off with a blind flange.
Plate Flanges
Plate flanges, also known as Flat flanges, have a gasket surface that is in the same plane as the bolting circular face. The flat-faced flange is another name for it. Flat face flanges are frequently used in applications where the mating flange or flanged fitting is cast. When the counter-flanges are the flat face, flat face flanges are employed.
This issue is most common when Cast Iron equipment, valves, and specialty are involved. The raised face of the carbon steel flange must be removed when attaching flat face cast iron flanges to carbon steel flanges. According to ASME B31.1, a full face gasket is required.
Slip-On Flanges
The flange that slips on is essentially a ring that is placed over the pipe’s end, with a flange face that extends far enough from the pipe’s end to apply a welded bead to the inner diameter. Slip-On Flanges, as their name implies, are flanges that slip over a pipe. SO flange is another name for a slip-on flange. It’s a type of flange with an interior design that’s slightly larger than the pipe and slips over it.
The top and bottom of the flange can be immediately linked to equipment or pipe by fillet welding the SO flange since the inner diameter of the flange is slightly larger than the external dimension of the pipe. It’s utilized to get the pipe into the inner hole of the flange. With a raised or flat face, slip-on pipe flanges are employed. For low-pressure applications, Slip-On Flanges are a good choice. Many fluid pipelines make extensive use of slip-on flanges.
Weld Neck Flanges
A tapered hub flange, sometimes known as a high-hub flange, is a type of weld neck flange. The weld neck flange (WN flange) has a neck that can transfer the pipe tension, decreasing the pressure in the flange’s bottom. It can be used in pipelines that operate at high or low temperatures and can sustain a lot of pressure. The long tapered end of a Welding Neck Flange, which gently passes through the wall thickness from a pipe or fitting, is easily visible.
For usage in a variety of applications involving high pressure, sub-zero, and/or extreme temperatures, the long tapered hub provides significant shielding. A circular fitting with a projecting edge around the circumference makes up a weld neck flange. Pressures of up to 5,000 psi have been successfully employed with the Weld Neck Flange.
Socket Weld Flanges
Socket weld flanges have only one fillet weld on the outside and are often not recommended for important services. Small-bore lines are mostly served by them. They have the same static strength as Slip-On flanges, however, they have a 50% higher fatigue strength than double-welded Slip On flanges. To ensure adequate bore length, the thickness of the connecting pipe should be defined for this type of flange. Before welding, a gap between the flange or fit and the pipe must be produced in the socket weld flange.
The bottom clearance of a socket weld is designed to reduce residual pressure. At the weld root that can occur during weld metal solidification. The disadvantage of the socket weld flange is the right gap that must be created. Corrosive products can cause corrosion difficulties in the crack between the pipe and the flange, which is particularly common in stainless steel pipe systems. Some processes prohibit the use of this flange. That concept must always be welded first by a pipe and then by a fitting for this flange.
