At what pressure does the combination exhaust relief valve lift?

The correct answer is that the combination exhaust relief valve lifts at a pressure that is 2 psi above the line pressure. This design ensures that the valve only opens when the pressure exceeds the operational limits, allowing for safe and efficient handling of excess pressure within the system.

It’s essential for the valve to lift at this specific pressure above the line pressure to protect the system from potential damage due to overpressure conditions. By lifting at 2 psi above, the valve provides a buffer that accommodates normal fluctuations in pressure during operation while still acting quickly enough to mitigate risks when pressure rises unexpectedly.

Other pressure thresholds, such as 1 psi, 5 psi, or 10 psi, do not provide this optimal safety margin relative to the line pressure, potentially allowing too much pressure to build up before relieving it, which could lead to system failures or safety hazards.