TYPES & APPLICATIONS

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 manufacturers 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 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 interval weld may be applied in high stress applications. It’s biggest use is in high pressure systems such as hydraulic and steam lines.

Lap-Joint Flanges

This is again similar to a slip-on flange, but it has a radius at the intersection of the bore and the flange face toaccommodate a lap stub end. The face on the stub end forms the gasket face on the flange. This type of flange is used in applications where section of piping systems need to be dismantle quickly and easily for inspection or replacement.

Spectacle Flanges

This is a pressure retaining plate with one solid end and one open end connected with a web or tie-bar. In normal operation, the open end forms the seal between two flanges and permits normal flow of fluid through pipe work. If the solid end is swung into position it effectively blanks of the pipe and halts the flow.