🔍 Key Concepts

• Identify how the stem threads are cut and how turning the hand wheel moves the stem up or down in Figure A. • Determine the function of parts #4 and #8 – are they packing/gland components or a locking device that must be loosened before the stem can turn? • Recall normal operation of a rising‑stem globe valve ("lefty‑loosey/righty‑tighty" as viewed from the operator’s position) and when that might be reversed.

💭 Think About

• Look closely at the cross‑section in Figure A: if the hand wheel turns clockwise from the top, does the stem move toward or away from the valve seat? What about counterclockwise? • Ask yourself whether the valve could operate properly if you had to loosen #4 or #8 every single time you opened or closed it. What does that suggest about the purpose of those parts? • Compare Figure A and Figure B: which one shows the valve open and which shows it closed? From that, infer which direction the hand wheel must have been turned.

✅ Before You Answer

• Verify whether #4 is clamping sealing/packing material around the stem (meaning it normally stays tight during operation) or actually locking the stem from turning. • Verify whether #8 is part of the body/bonnet structure or a separate lock that must be released – look at whether it directly contacts the hand wheel or stem. • Before choosing, trace the thread path: imagine the stem nut fixed in the bonnet and decide which rotation of the hand wheel will raise the stem and lift the disc off the seat.