Table 3-3. Preventive Maintenance Checks and Services for ROWPU System (Continued)
Q - Quarterly
S - Semiannually
A - Annually
CHECK FOR AND HAVE
IS NOT READY/
REPAIRED OR ADJUSTED
B D A D W M Q S A
c. Remove used filter elements. Keep upper
seals separate from lower seals.
Examine used filter elements. If they con-
tain large amounts of sand the frequency of
replacement has increased, check media fil-
ters for internal damage.
d. Discard used filter elements.
e. Clean internal parts and inside of filter
housing with a stiff bristle brush and
clean water and dry with clean, lint-free
f. Inspect upper and lower spiders. Check
Spiders are bent.
seals for damage and replace if nicked.
Place new or reused upper seals in sockets
on upper spider. Place lower seals on
guide pins on lower spider.
g. Place three new filter elements in three
center sockets on upper spider. Make
sure upper seals remain properly seated.
h. Place lower spider on assembly so that
tie rod holes on spider align with tie rods
and center guide pins just engage filter
i. Make sure seals remain in sockets and
place nine outer filter elements in outer
sockets on upper spider. Make sure
upper and lower seals are properly
seated for each filter.
j. Install six washers, three springs, and
Springs are missing.
three hex nuts on spider tie rod ends.
Hand tighten until nuts contact top washers.
Tighten hex nuts evenly another
seven turns each to compress but not to
completely flatten spring.