NFPA 1901 requires that a pressure control valve to operate within ______ following a rise in pressure and permits no more than a _____ increase above it set pressure?

NFPA 1901 requires that a pressure control valve to operate within ______ following a rise in pressure and permits no more than a _____ increase above it set pressure?

• A. 3-10 sec, 30 psi
• B. 1-3 sec, 15 psi
• C. 5-15 sec, 20 psi
• D. 0-2 sec, 10 psi

Answer: (A)

The main idea is that the pressure control valve must respond quickly to a rise in pressure and keep the overshoot small. NFPA 1901 specifies that the valve should actuate within a window of 3 to 10 seconds after pressure begins to rise, and it may not allow the pressure to rise more than 30 psi above its set pressure. This balance—fast enough to prevent dangerous pressure buildup, but limited enough to avoid excessive relief—helps protect the system components and maintain stable operation. Other time ranges (too fast or too slow) and other overpressure limits (lower than 30 psi) don’t align with the standard, which is why the chosen values match the requirement.

The main idea is that the pressure control valve must respond quickly to a rise in pressure and keep the overshoot small. NFPA 1901 specifies that the valve should actuate within a window of 3 to 10 seconds after pressure begins to rise, and it may not allow the pressure to rise more than 30 psi above its set pressure. This balance—fast enough to prevent dangerous pressure buildup, but limited enough to avoid excessive relief—helps protect the system components and maintain stable operation.

Other time ranges (too fast or too slow) and other overpressure limits (lower than 30 psi) don’t align with the standard, which is why the chosen values match the requirement.