[W126 Coupe] Cat replacement

[Richard Hesek]

 Hello,
 My new catalytic converter showed up last night and I have a question
regarding the twin pipe connections at the center muffler.
 This is an 87 560SEC US (non-Calif) cat, one pipe from the engine into the
cat and 2 pipes out to the back.

  The two pipes out have a different connection to the center muffler. One
is flared and has the 2 bolt flange captivated. The other pipe is straight
and appears to simply slip into the corresponding mate at the center
muffler.
  The diagram in job 49-100 looks as though this connection is a
compression type where the seal ring is squeezed between flanges and
compresses down against the pipe.

  Is this standard?

Thanks,
 Rick Hesek