Introduction
This 3D model shows a typical setup of two safety relief valves on a single manifold. This type of setup is often employed where a catastrophic failure of machinery downstream would have significant financial impact, or, loss of life.
The second Safety Relief Valve (SRV) adds a layer of safety as normally only one SRV must operate in order to relieve the highest possible pressure accumulation rate.
Additional Resources
http://www.refrigerationcomponents.ca/Products/Parker/rs/bulletins/relief_valves/70-01.PDF
https://www.spiraxsarco.com/learn-about-steam/safety-valves/types-of-safety-valve