🔍 Key Concepts

• Look closely at how piece #3 (needle valve) is attached to piece #2 (test valve body) in the cross‑section drawing. • Think about common methods used to secure adjustable parts like a needle valve so they can be turned in and out repeatedly without loosening or falling out. • Consider what a threaded connection or a press fit would look like in a sectional mechanical drawing.

💭 Think About

• In the illustration, can you see any symbol or pattern that represents threads between pieces #2 and #3? What would that suggest about how they are held together? • If the connection needed to be adjustable and removable for maintenance, which of the listed options would be most practical in real shipboard equipment? • Which of the options would be unlikely for a precision component that must seal under pressure yet still be adjustable by hand?

✅ Before You Answer

• Carefully inspect the boundary between #2 and #3 for thread detail or any sign of welding or clamping hardware. • Ask yourself whether a fillet weld would allow the needle to move as a valve and be serviced later. • Eliminate any option that would prevent the needle from being turned or removed for maintenance or adjustment.