Here are some common maintenance tasks that should be performed on threaded valve:

Inspect and clean threads

Remove any debris, corrosion, or built-up material from threads. Wire brush if needed.

Inspect PTFE tape/thread sealant

Replace if worn out. Reapply new thread sealing material as needed.

Tighten packing nuts

Ensure gland nuts that compress the stem packing are tightened to prevent leaks.

Lubricate stem threads

Apply thin coat of lubricant like grease to exposed stem threads to prevent corrosion and ease operation.

Test valve operation

Cycle the valve open and closed by turning the handle to ensure smooth operation. Look for signs of wear.

Replace worn components

Rebuild kit includes seats, seals, stems etc. Replace these parts if showing signs of deterioration.

Exercise infrequently used valves

Open/close valves at least quarterly that see low use to prevent seizing.

Inspect flanges/fasteners

Check bolting for leaks or looseness and tighten if needed. Replace worn-out bolts.

Document maintenance

Note date, tasks done, and any issues found in a valve maintenance logbook.

Regular care prevents threaded valves from failing prematurely due to lack of routine maintenance and component wear.