You might have misunderstood me! This is not a standard API 520 configuration.

Piping Snubber is not a common hardware as a open discharge PSV outlet support, rigid support is, if it is taken from same header from which PSV inlet is coming up!

But, special snubber with bypass eliminated can hold PSV thrust force for prolonged duration. Bergen Snubber & Restraint catalogue claims it.

reg,
sam