What is the difference between RTJ and RF?

RTJ flanges have grooves in their sealing faces, while RF flanges do not. If you want to make a connection between the two flanges, you can only apply a flat gasket. Further, the RTJ flange will be damage the gasket, especially if a spiral wound or metal jacketed gasket is applied.

What is ring type joint flange?

A Ring type joint flange(RTJ) is a machined metallic ring with a deep groove cut into its face. This groove rests a metal ring which gets compressed when the connecting bolts of the flange are tightened. This compression results in a leak-proof, close-fitting seal on the pipe or connection.

What is the difference between flat face and raised face flange?

The difference between a raised face and a flat face flange is that the raised face has a raised area that surrounds the pipe bore and the flat face flange doesn’t. These are two of the most commonly used types of flange faces.

What does Raised face flange mean?

The Raised Face flange is the most common type used in process plant applications, and is easily to identify. It is referred to as a raised face because the gasket surfaces are raised above the bolting circle face.

Is a lap joint flange raised face?

The lap joint flange can be used in sizes and pressure classes similar to that of a weld-neck flange. The nature of this joint means that the stub end facing is also the flange facing, which makes it raised faced, and the gasket seating surface.

What is FF and RF flange?

The flange face is the surface area that hosts the gasket. The 6 available types of flange face are flat (FF), raised (RF), ring joint (RTJ), lap joint, male and female (M&F), tongue and groove (T&G). RF and FF flanges may have different types of “finish” (i.e. roughness on top the surface): smooth, stock and serrated.

What are the different types of flanges?

Most commonly used flanges are weld neck flange, slip on flange, blind flange, socket weld flange, threaded flange and lap joint flange (RTJ Flange). This type of connection in a pipe flange allows for ease of disassembly and separation for repair and regular maintenance.

What is smooth finish flange?

Smooth finish flanges are more common for low pressure and/or large diameter pipelines and primarily intended for use with solid metal or spiral wound gaskets. Smooth finishes are usually found on machinery or flanged joints other than pipe flanges.

What is the difference between a weld neck flange and a lap flange?

The hub is the same outside diameter as the raised face (gasket contact surface) of a weld neck flange. Lap joint pipe flanges slide directly over the pipe and are most commonly used with stub end fittings. A pipe is usually welded to the Stub End and the Lap Joint pipe flange is free to rotate around the stub end.

What is the difference between lap joint flange and slip on flange?

lap joint flanges are very similar to a slip-on flange, with the main difference being that it has a curved radius at the bore and face to house a lap joint stub-end. Lap joint flanges and stub-end assemblies are typically used in situations where frequent dismantling is required for for inspection.

Are lap joint flanges raised face?

How do I choose a flange?

Guidelines for Selection of Various Types of Flanges

1. Pressure Temperature Rating of Flanges.
2. Flange Dimensional Standards.
3. Flange Facings.
4. The bore of Welding Neck Flanges and Hub Design.
5. Flange Material Limitations.
6. Iron Flanges.
7. Carbon Steel Flanges.
8. Low and Intermediate Alloy Steel Flanges.

What’s the difference between flat and raised Face flanges?

1 Raised Face height. 2 Flat Face (FF) The Flat Face flange has a gasket surface in the same plane as the bolting circle face. 3 Ring-Type Joint (RTJ) The Ring Type Joint flanges are typically used in high pressure (Class 600 and higher rating) and/or high temperature services above 800°F (427°C). 4 Ring Type Joint gaskets.

Which is the most common type of flange face?

The raised face is the most common flange face type used. It’s called a raised face because it has a raised surface above the bolting circle where the gasket is placed. Sealing this type of flange face is accomplished by compressing a soft, flat, or semi-metallic gasket between mating flanges in the raised area of the flanges.

What do you need to know about RF flanges?

Sealing this type of flange face is accomplished by compressing a soft, flat, or semi-metallic gasket between mating flanges in the raised area of the flanges. Raised face (RF) flanges are common in process plant applications but can be used in almost all applications. They are suitable for use in high and low temperatures and pressures.

Can a ring type gasket be used on a raised flange?

Like the ring-type gasket, this can also seal raised flange faces, but will have an OD the same as the flange. That means it needs holes for the securing bolts to pass through, and these help locate the gasket on the flange, making alignment easier.