What is the minimum threshold used to define a high-pressure system that requires double barrier protection?

• A. >1000 psi
• B. >100 psi
• C. >2000 psi
• D. >500 psi

Answer: (A)

The key idea is when stored energy in the system becomes high enough that a single barrier could not reliably prevent a dangerous release. Safety standards set a cutoff for what counts as high‑pressure, and above that point a second, independent barrier is required to provide defense in depth. That double containment helps ensure containment even if the primary barrier fails, greatly reducing the risk to personnel and the environment. The other pressure levels are below that defined threshold, where standard containment and safety features suffice without a second barrier.