Steam Relief Valve Vent Design

[RRE]

I am looking for a design reference that would enlighten me on the proper design of a steam relief valve vent (discharge) piping. A failure resulted in the inlet piping to a steam relief valve. The valve had a sizeable vent pipe that was supported. The weight (forces) of that vent pipe is coming into question as a possible failure mechanism. Where can I find how that vent pipe needs to be designed for a steam relief valve?? Kind regards