what is a Flange?

A flange is an external or internal ridge, or rim, for strength, as the flange of an iron beam such as an I-beam or a T-beam; or for attachment to another object, as the flange on the end of a pipe, steam cylinder, etc., or on the lens mount of a camera or for a flange of a rail car or tram wheel. Thus flanged wheels are wheels with a flange on one side to keep the wheels from running off the rails. The term "flange" is also used for a kind of tool used to form Long Weld Neck. Pipes with Long Weld Neck can be assembled and disassembled easily there are different types of Long Weld Neck Material and they are ASTM A105 Long Weld Neck, ASME A105 Long Weld Neck Flanges

ASTM A266 GR.1 Long Weld Neck, GR.2 Long Weld Neck Flanges, GR.3 Long Weld Neck, GR.4 Long Weld Neck 

ASTM A350 LF1 Long Weld Neck, LF2 CL1/CL2 Long Weld Neck, LF3 CL1/CL2 Long Weld Neck 

ASTM A694 F42 Long Weld Neck, F46 Long Weld Neck, F48 Long Weld Neck, F50 Long Weld Neck, F52 Long Weld Neck, F56 Long Weld Neck, F60 Long Weld Neck, F65 Long Weld Neck, F70 Long Weld Neck.

As you can see there are many types of Material that can be used to manufacture Long Weld Neck.

Other than the once that I have already Named there are other sets of material that can be used and they are Stainless Steel, Alloy Steel, Carbon Steel, Aluminium, Duplex Steel, Hastelloy, Incoloy, Inconel, Monel, Nickel Alloy, Nitronic Alloy, Titanium.

What material is used also depends on what are you using your Flanges for, and there are many other uses of Flanges and they are,

Slip-On Flange

The flange is slipped over the pipe and then welded both inside and outside to provide sufficient strength and prevent leakage. This flange is used in preference to weld necks by many users because of its lower cost and the fact that less accuracy is required when cutting pipe to length.

Blind Flanges

This is a flange without a bore and is used to shut off a piping system or vessel opening. It also permits easy access to vessels or piping systems for inspection purposes. Blind flange can be supplied with or without hubs at the manufacturer's option.

Weld-Neck flange

This is designed to be joined to a piping system by buttwelding. It is relatively expensive because of Its long neck but is preferred for high-stress applications. The neck or hub transmits stresses to the base of the hub to the wall thickness at the butt weld, provide important reinforcement of the flange. The bore of the flange matches the bore of the pipe, reducing turbulence and erosion.

Threaded Flange

This is similar to a slip-on flange in outline, but the bore is threaded, thus enabling assembly without welding. This obviously limits its application to relatively low-pressure piping systems. The flange may be welded around the joint after assembly, but this is not considered a satisfactory method of increasing its applications.

Socket Weld Flanges

This is similar to a slip-on flange in outline, but the bore is counter-bored to accept pipe. The diameter of the remaining bore is the same as the inside diameter of the pipe. The flange is attached to the pipe by a fillet weld around the hub of the flange. An optional internal weld may be applied in high-stress applications. It's the biggest use is in high-pressure systems such as hydraulic and steam lines.