a pleasant day to everyone here on this forum.

right now, im working on a open type PSV. the outlet is going to the atmosphere. i have 2 supports on the outlet, dummy support on the bend and all-around guide on the straight pipe going to the atmosphere. system is 400 deg C. my configuration is like this:

on the guide ( 15 mm gap on z, 3 mm gap on x)
on the dummy ( fixed support x,y,z w/ no gaps)

is this ok? or my 15 mm gap on the guide on the straight pipe will cause too much movement? but i need that gap for thermal expansion. i need your help guys. thanks...