3.563.5275.210
6
4. Maintenance
4.1. Procedure for renewing stem seals (Fig.2.)
a) Isolate the valve.
b) Remove actuator from valve.Refer to Installation and Maintenance Instructions covering Spirax
Sarco Actuators.
c) Remove locknut (1).
CAUTION: Care should be taken in removing the stem seal since fluid under pressure may be
trapped between the isolating valves.
d) Unscrew the bonnet nuts (8) and withdraw the bonnet (12) taking care not to damage the
spindle surface.
e) Unscrew and remove gland nut (2). By mean of a hooked tool in soft metal like brass, remove
the gland ring set (3), the washers (6) and the spring (4).
f) Examine parts for signs of damage or deterioration and renew as necessary. Note that score
marks or scaly deposits on the valve stem (5) will lead to early failure of the seals.
Clean parts taking care to avoid scratching the stem or bore of the packing chamber.
See paragraph 4.3 for renewing valve stem (5).
g) Refit the bonnet and finger tighten the bonnet nuts.
h) Insert washers, spring and new gland ring seals into the packing chamber following the
sequence shown in fig.1, care being taken to avoid damage to the sealing edges.
i) Refit the gland nut (2) and tighten until resistance is felt and unscrew two turns.
j) Ensure that the stem (5) moves freely.
k) Refit valve lock nut (1).
l) Bring the valve back into service
m) Check for leakage at gland.
Chart of Recommended Torques (Nm)
Size Seat Bonnet Nuts Plug Nut & Lock Nut
DN (9) (8) (13/14)
150 270-290 150-160 230-250
200 320-340 110-120 230-250
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