Flange spacing RTJ gasket 1

[fmmo]

Hello,

For a Dutch gas project, we are engineering a flowline, containing several 9" API 10000# flanges.
On this project, I am working as a piping designer and trying to determine the space between the flange facings, after the full boltload is applied. The RTJ gasket is of a BX157 type.

Apparently some types of RTJ flange connections provide a space between the facings, resulting in excessive noise production.
Can anyone tell me if the mentioned connection eliminates the space between the flange facings, or do we have to take specific actions?

Kind regards,
FMMO

 

[gr2vessels]

fmmo,
If you leave a gap between the RTJ flanges, can you guarantee even tension on each bolt and maintain full axial alignment of those flanges? I guess not. Hence no gap between flange facings. Check out also the Norsok flanges, they are similar and the installation instructions on the web are extensive.
cheers,
gr2vessels

 

[mattweb]

API Type 6BX Flanges (as defined in API 6A) that use BX gaskets are designed to be made up face-to-face with no gap between the flange faces. After make-up there is often a small gap though depending on machining tolerances and make-up torque applied.