🔍 Key Concepts

• Spring-loaded safety valve mechanics – which way the spring is pushing on the disc in the closed position • System (sensed) pressure under the disc – which direction that pressure force acts, relative to the disc and the seat • Opening vs. closing forces – which force must dominate for the valve to lift, and which one keeps it seated

💭 Think About

• Look at the illustration and imagine the valve in the normal closed position: is the spring trying to push the disc onto the seat or away from it? • For fluid pressure in the huddling chamber under the disc, does that pressure tend to lift the disc off the seat or push it harder against the seat? • Based on your answers above, match which statement correctly labels the spring as either an opening or closing force, and the sensed pressure as either an opening or closing force, with the right directions (upward or downward).

✅ Before You Answer

• Be sure which way the spring force acts on the disc in the closed position (up or down). • Confirm which side of the disc the sensed pressure acts on in this design (underneath or above the disc). • Verify that the option you choose has spring = closing force and pressure = opening force, or vice versa, consistent with how a spring-loaded safety valve must behave.