🔍 Key Concepts

• Study the piping immediately downstream of each pump symbol (bilge, ballast, and general service) in illustration GS-0042. • Recall that a relief valve on the discharge side is usually shown as a small line leaving the discharge piping and returning to a tank or suction side, with a valve symbol. • Think about which pumps are commonly centrifugal vs. positive displacement, and which type normally requires a discharge relief for protection.

💭 Think About

• For each of the three pumps, trace the discharge line and ask: Do I see a valve symbol with a small bypass/return line going back to a tank or suction? • Compare the bilge, ballast, and general service pump drawings: Which one(s) clearly show an extra valve and a return line off the discharge, instead of just a check valve and straight piping? • Ask yourself: If the discharge valve were accidentally closed, which pump would be most at risk of damage from overpressure, and does the drawing reflect this with a relief valve?

✅ Before You Answer

• Verify the symbol you are calling a relief valve actually has a branch line leading away from the discharge and returning to a tank or suction, not just a simple check valve in line. • For each pump, confirm whether the discharge piping has only check/stop valves or an additional valve with a bypass line that could serve as a relief. • Before picking an option like "All of the above", double‑check that each individual pump really shows a distinct relief/bypass arrangement on its discharge in the illustration.