If a safety valve lifts at 100 psi, what is the expected closing pressure?

In the context of safety valves, the expected closing pressure is typically referred to as the "blowdown" pressure, which is the range of pressure at which the valve will close after it has lifted. Safety valves are designed to prevent overpressure in a system by venting excess pressure, and they must close to maintain the operational pressure criteria specified for the system.

When a safety valve lifts at a certain pressure, it doesn't immediately close at that same pressure. Instead, it allows a small amount of pressure to drop before it seals again. For a valve that lifts at 100 psi, the closing pressure will be below this point by a certain margin, which is determined by the specific design and settings of the valve.

The expected closing pressure of 96 to 98 psi is reasonable, given typical industry practices. This range indicates that the valve allows for sufficient blowdown so that it does not prematurely reseat and potentially risk overpressure in the system. Selecting this option reflects an understanding of safety valve operation in terms of ensuring reliability and safety in a pressure regulation context.

The other options fall outside the typical blowdown range for a valve lifting at 100 psi, where a closing pressure considerably below or above this range would not align with conventional safety