Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10 Page 11 Page 12Australian Pipeline Valve - Installation, Operation and Maintenance Manual 6 SOFT SEATED PLUG TYPE NEEDLE VALVE - S-H1, S-M5A, S-M5F, S-M9S 3.1 STEM SEAL REPLACEMENT Teflon and Graphite seals/packings do not often need replacement if leakage occurs usually the leak can be stopped by tightening the bonnet bushing. 1. Refer to Table A in the Appendix for identification of parts. The design may vary according to size, rating special bonnet options, and trim. Refer to the as-built drawing supplied with the data package. 2. Remove bonnet lock pin (item #10) from valve body, using pliers or wire cutters. 3. Unscrew bonnet counter-clockwise to remove bonnet assembly from the valve. 4. Place bonnet in soft-jawed vice to facilitate disassembly. 5. Remove T-bar handle (part #2) by loosening grub screw (part #1). 6. Remove plastic dust cover (part #4) from gland retainer bush (part #5). 7. Loosen lock nut (part #6) and unscrew bush off stem. 8. Remove valve stem (part #3) from bonnet (part #7) by screwing downward. 9. Remove Teflon or Graphite stem packing (part #9) and the two washers (part #9a). 10. Slide out the complete plug & spindle (part #12) and thrust washer (part #12a), (only on some models). 11. Clean all parts with suitable cleaner such as acetone. 12. Inspect all parts for damage; especially the threads and stem tip area. Replace both the stem and bonnet bush if threads do not engage smoothly. 13. Lubricate the stem (part #3) threads and bush (part #5) with lubricant resistant to the service in which the valve is being used. 14. Re-insert the stem and tip (part #3/3a) into the end of the bonnet that is threaded externally. 15. Push the stem upward from the bottom of the bonnet. 16. Place the stem packing (part #9) and packing washers (part #9a) over the stem and push it down into the bonnet. 17. Place the retainer bush (part #5) with lock nut (part #6) over the stem and hand screw the threads. Screw the bushing down into the bonnet until it reaches the stem seal. 18. Place the dust cover (part #4) over the valve stem (part #3). 19. Place the handle (part #2) and tighten the grub screw where applicable (part #1) to 1.38-1.66 kg-m (10-12 ft·lbs). Take care not to bend the stem. Do not attempt to replace stem packing in-line, especially if under line pressure.