GLOBE VALVES OS & Y - FORGED - ISO 15761/API 602/B16.34
Australian Pipeline Valve - Installation, Operation and Maintenance Manual
17
FIGURE 5
Lubrication
Points
Globe Valve - Top Works
(no grease fitting)
Globe Valve - Top Works
(single grease fitting)
4 . 0 EXTRAORDINARY REPAIRS &
MAINTENANCE
Due to the relatively low replacement cost of small diameter standard carbon steel valves under, it is usually
less expensive to replace the complete valve than to have maintenance personnel effect repairs. Generally,
the only justifiable repairs are replacement of packing and gaskets as previously described.
Always replace the bonnet gasket whenever a valve is disassembled. ‘Pressure seal’ style bonnet valves (see
example drawing Appendix C) require a proprietary gasket. After removing valve from line, use adequate
force to remove bonnet. Gasket seating surfaces should be scraped clean (avoid radical marks). Bonnet bolts
should be tightened in a diagonal pattern at several different increasing torque settings until the final
recommended torque value is attained. Refer to Tables A & B in Appendix A, and Figure 10.
Other specialty packing such as V-ring Teflon will require that the valve be disassembled if repacking is
required.
4.1 STEM
If the stem locks or “freezes”, causes can generally be attributed to dry worn packing or a dry yoke nut. In
either of these cases, the following service is required:
a) Unscrew gland nuts, remove the gland flange and bushing to expose stem packing and packing spacer
(where one is fitted). Replace stem packing if it is damaged.
b) Check lubrication of yoke nut. If it is dry, remove the yoke nut but determine if there is evidence of seizure
marks. If so replace it with a new yoke nut.
4.2 GLAND DISASSEMBLY & REPLACEMENT OF STEM PACKING
In those cases where the valve cannot be removed from the piping system, it is important that prior to
servicing, the valve be opened to its fullest extent and purged of any pressure/fluid (protective safety
goggles should be worn).
a) Australian Pipeline Valve graphite or PTFE and graphite packing sets are usually die formed and have no
end cut. As a result, these rings cannot be replaced without removing the valve bonnet. If the valve is to be
