Forged Steel FLANGE ANSI B16.5 ANSI B16.47 Slip On Lap Joint Bind Socket Welding Neck

Are slipped over the pipe and then welded from both inside and outside to provide sufficient strength and prevent leakage. This flange is used instead of weld necks by many users because of its lower cost and also the fact that it requires less accuracy when cutting pipe to length. Slip-Ons are not normally used in high-stress applications due to low hub and weld attachment.                                            

Also known as a high-hub flange or a tapered hub flange, weld-neck flanges are designed to be joined to a piping system by butt-welding. Weld Neck flanges are preferred when piping is subject to high stresses, high-pressures or subzero/elevated temperatures. The neck, or hub, helps to transmit environmental stress at the flange with the pipe to which it is welded to. The gradual transition of thickness from the base of the hub to the wall thickness at the butt weld provides important reinforcement of the flange. Turbulence and erosion are reduced due to the matching bore size of the pipe and flange. These flanges are bored to match the ID of the mating pipe so there is no restriction of flow.

Similar to a slip-on flange in design, but with a bore that is counter-bored to accept pipe. The diameter of the remaining bore is the same as the inside diameter of the pipe. A fillet weld around the hub of the flange attached the flange to the pipe. An optional interval weld may be applied in high stress applications. Its biggest use is in high pressure systems such as hydraulic and steam lines.

Used for special circumstances with their main advantage being that they can be attached to the pipe without welding. Sometimes a seal weld is also used in conjunction with the threaded connection. Although available in most sizes and pressure rating, threaded flanges today are used almost exclusively in smaller pipe sizes. Threaded flanges are not suitable for piping with thin wall thicknesses because cutting a thread on the pipe is not possible.

Nearly identical to a slip-on flange, but having a radius at the intersection of the bore and the flange face to accommodate a lap stub end. These flanges slip over the pipe and are not otherwise welded or fastened to it. Bolting pressure is transmitted to the gasket by the pressure of the flange against the back of the pipe lap (stub-end). The face on the stub-end forms the gasket face of the flange. Lap-Joint flanges do not have raised faces and a single connection requires both lap-joint flange and a pipe stub-end. They are best used where sections of piping systems need to be dismantled quickly and easily for inspection or replacement.

Blind Flanges do not have a bore and are used to shut off a piping system or vessel opening. Its design permits easy access to vessel or piping system for inspection purposes. It can be supplied with or without hubs at the manufacturer’s option. In terms of internal pressure and bolt loading, blind flanges, especially in the larger sizes, are the most highly stressed flange types.