Lap joint flange facing

[KunAbdel]

In weld neck flanges we specify the facing of the flange for example raised face (RF) and based on that we use a specific gasket to match the facing of the flange

What about lap joint? In autocad plant 3d I can only find Flat face (FF) in the catalogue is it true?

 

[EngrPaper]

The hub of the lap joint forms a raised face. The backing ring sits behind the hub.

 

[LittleInch]

The hub of the flange is normally the same size as the RF bit of an RF flange.

I've never seen a RTJ lap joint.

 

[KunAbdel]

The hub of the flange is normally the same size as the RF bit of an RF flange.

I've never seen a RTJ lap joint.

i just saw a picture on the internet of a stub end with RTJ facing
Also i saw something in ASME B16.5 idk if it is related or not --> para 6.4.3.4

need someone to confirm

 

[LittleInch]

Someone might make one but that flange is not an RTJ. I was just saying I had never seen one, not that it wasn't possible to get one.

It's defiantly got a square edge groove so looks like either a large O ring or half of a tongue and groove.

I know the website says RTJ, but it isn't.

 

[KevinNZ]

I implemented RTJ lap flanges. Custom made from two WN flanges to allow rotation in the site assembly.

 

[LittleInch]

Custom made says it all....

 

[KunAbdel]

I implemented RTJ lap flanges. Custom made from two WN flanges to allow rotation in the site assembly.

Do you have any pictures you can share?

 

[Gator]

The hub of the lap joint forms a raised face.

So there's no grooving as there is with other flange faces.