Assume rotational stiffness is for the expansion joint without tie rods. Assume tie-rods halt expansion joint rotation - seems to be manufacturer intent.

Expansion joint = nodes 10-20, 30 mm long, stiffnesses as listed.
Effective diameter = (46.53 / pi)^0.5*2

Tie rod = 0 weight rigid node 10-21. Axial restraint with 30mm gap on node 21, cnode 20.
Vertical and lateral restraint with 4mm gap on node 21, cnode 20.
RX/Y/Z no gap, node 21, cnode 20.

You're "supposed to" install an anchor on the pipe near the expansion joint, preferably inline.

CAESAR will estimate the stiffness of the tie-rods to be that of the same diameter pipe and thickness, but thickness x 10. Not great, not bad, but likely "close enough."

Run the analysis. Provide a cursory review of vertical, lateral, and rotational loads. Do they seem reasonably able to be absorbed by the tie-rods?

Depending on the equipment, you're going to find that the pressure thrust alone overloads the equipment. In this case, you should close the gap on the far end of the expansion joint. I.E. instead of x with 30 mm gap, it's a +x with gap, -x without gap.

Also depending on the nozzle sensitivity, you might have to make that 0 weight rigid weigh 97.5 kg, and pick the better orientation, and have them swap the flow orientation of the expansion joint as needed.