6
KTM
POWDER DISCHARGE SYSTEM (PDS) METALTITE
®
BALL VALVES
INSTALLATION, OPERATION AND MAINTENANCE INSTRUCTIONS
8 MAINTENANCE
The following instructions will contribute to a
long life service of the valve. Periodical checks
and maintenance are required to keep valves
in good working condition. Parts to be checked
periodically and maintenance items are shown
in below Figure 4.
CAUTION
If leakage is observed through the gland packing,
tighten the gland bolts slowly and evenly until
the leakage stops. This must be accomplished
without affecting the torque. Do not over-tighten
the packing gland bolts, since this will increase
the torque required to operate the valve.
This procedure should be performed every 3,000
operation cycles or every six months of service.
When gland packing is expected to be loosened
due to the heat cycle, retighten the screws every
two months of service or every 1,000 operational
cycles.
Typical structures of gland portion are shown
in Figure 4. Numbers of parts vary slightly
depending on the valve type and size. Refer
to the respective construction drawings for
details.
CAUTION
The sealing portion between body and body cap
is provided with reinforced PTFE or a graphite
gasket as shown in Figure 5. In case of slight
leakage, the fastening bolts should be moderately
tightened.
FIGURE 4
Gland structures
FIGURE 5
Body sealing structures
Gland bolt
Gland bolt
Gland nut
Gland nut
Nut
Gasket
Body
Stud
Gland flange
Gland packing
Extended bonnet
Stem
