🔍 Key Concepts

• Identify which part in the illustration actually changes the spring compression on the valve disc. • Understand the purpose of the adjusting ring versus the compression screw on a spring-loaded safety valve. • Relate greater spring force to higher popping (set) pressure required to lift the disc.

💭 Think About

• Look at the spring in the illustration: which component, when moved, would squeeze or relax that spring along its axis? • What is the main difference between a ring located near the nozzle/disc area and a screw threaded through the top bonnet? How would each affect flow vs. set pressure? • If the valve must wait for a higher pressure before opening, should the spring be made harder to lift or easier to lift?

✅ Before You Answer

• Verify in the illustration which part is labeled as the compression screw and how it bears on the top of the spring. • Verify which part is labeled as the adjusting ring and note that it sits near the nozzle/throat, influencing blowdown/simmer, not basic set pressure. • Before choosing, mentally trace: "If I move this part in the indicated direction, do I increase or decrease the spring’s initial compression?" — that change must match a higher popping pressure.