What is difference between RF and RTJ flanges?
Answer: RF means “Raised Face.” RTJ means “Ring Type Joint.” RF flanges seal with a flat gasket, formerly made of asbestos but now made of more environmentally friendly material, designed for installation between the raised faces of two mating flanges (both with raised faces).
Why do flanges have a raised face?
Raised Face and Flat Face The raised face is intended to decrease the surface area of the seal, thus concentrating the surface pressure applied when mating the flange. The result is a stronger seal. The raised face has a machined serrated finish that will bite into the gasket whenever pressure is applied.
What are different types of flanges?
Common Flange Types and Characteristics
- Threaded Flanges. Also known as a screwed flange, this style has a thread inside the flange bore which fits with the matching male thread on the pipe or fitting.
- Socket-Weld Flanges.
- Slip-on Flanges.
- Lap Joint Flanges.
- Weld Neck Flanges.
- Blind Flanges.
- Specialty Flanges.
What are the different types of flanges?
When to use RTJ flange?
RTJ Flanges are used for high pressure applications up to pressures as high as 15,000 psi (103 MPa). It is only furnished only on steel or alloy valve bodies and usually need to specified when ordering. The flanges usually come in blind, slip-on, threaded and weld neck.
How do I know what flange I have?
You need to find the outer diameter, the inner diameter, the number of bolt holes, bolt hole diameter, and the bolt circle diameter. Bolt circle diameter (B.C.) is one of the most important measurements to make when identifying a flange.
Can you connect a flat face flange to a raised face flange?
Flat face flanges are never to be bolted to a raised face flange. ASME B31. 1 says that when connecting flat face cast iron flanges to carbon steel flanges, the raised face on the carbon steel flange must be removed, and that a full face gasket is required.
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 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.
Why are RF gaskets called Raised Face flanges?
Raised Face Flanges (RF) The Raised Face Flange is the most common type used in process plant applications, and can be easily identified. It is referred to as a face raised because the surfaces of the gasket are positioned above the face of the bolting circle.
Can a flat face flange be mated with a raised flange?
Flat face flanges (FF) have a contact surface having the same height as the bolting line of the flange. Full face gaskets, generally of the soft type, are used between two flat face flanges. According to ASME B31.3, a flat face flange should never be mated with a raised face flange as the resulting flanged joint would definitely leak.
What is a weld neck flange RF ( raised face )?
Zizi is manufacturer of ASME B16.5 forged steel pipe fittings and offers Weld Neck Flange RF in different dimensions. What is a Weld Neck Flange? It is very easy to identify a weld neck flange from the appearance because it has a high, tapered hub like a neck. This neck will be welded with pipe so it has the same wall thickness as pipes.
Why raised face flange?
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.
What is a full face flange?
• FLAT FACE (FF) The flat face (full face) flange has a gasket surface in the same plane as the bolting circle face. Applications using flat face flanges are frequently those in which the mating flange or flanged fitting is made from a casting.
What is a flange compensation ring?
Filler Flanges, also known as Compensation Rings, are used to connect flanges with raised faces or sealing surfaces-especially those of plastic lined steel pipe-to flat faced plastic flanges. Without filler flanges, when the bolts are tightened on such a joint, the plastic flange will, most likely, break.
What is a FF flange?
FLAT FACE FLANGE (FF) Flat face flanges (FF) have a contact surface having the same height as the bolting line of the flange. Full face gaskets , generally of the soft type, are used between two flat face flanges.
