Pressure balanced axial bellows

[KevinNZ]

Hi all

Which of these is the correct arrangement of tie rods for a pressure balanced axial bellows?



The first one does not look right and middle has too many locking nuts?

 

[LittleInch]

They are both just set up that way for transportation.

You will need to loosen off the bolts in the middle or the joint won't move axially to compress.

 

[mfgenggear]

I was puzzled. The intent of a bellows is to allow moment. I worked with lox fuel lines on the atlas centaur. And the reason for the bellows was to have slight movement from vibration, Prevent failure from cracking the joints.
So I was confused why the bolts.
Little inch cleared that up.

 

[goutam_freelance]

Third one (in red) is correct. The net force in piping from EXJ is close to 0 as the forces in higher diameter annular area balances the hydrostatic force in smaller area which is connected to piping.

But as @LittleInch said, the fixing arrangements shown appears to be temporary