🔍 Key Concepts

• Electric motor actuators used on shipboard piping systems • How gear reduction and a handwheel/declutch allow both powered and manual operation • Difference between driving a linear valve stem versus rotating machinery like a main engine or centrifuge

💭 Think About

• Look at the right-hand end of the drawing: does the long central shaft look more like a valve stem connection or a drive shaft for rotating equipment? • Notice the hand lever/handwheel assembly on the left: what does that suggest about needing local manual control of something that is usually operated from a distance? • Which of the answer choices most commonly uses a compact, sealed gear-motor unit with position control rather than continuous high-speed rotation?

✅ Before You Answer

• Identify whether the output motion is limited travel (quarter/half turn) or continuous rotation; match that to the most likely use • Check for parts that look like limit switches or position indicators, which are common on remote valve operators but not on jacking gears or centrifuge drives • Ask yourself which option is typically operated remotely and frequently in a piping system context on ships