TM 10-4610-232-12
CAUTION
Do not switch valve positions until media filter pressure drops below 3 psig (21 kPa).
(2)
Backwash step 2, air/water backwash (approximately 1 minute).
(a)
Clean/flush outlet valve V5 (1) - closed.
(b)
Media filter inlet valve V16 (2) - closed.
(c)
Backwash inlet valve V15 (3) - open.
(d)
Backwash outlet valve V17 (4) - open.
(e)
Media filter outlet valve V35 (5) - closed.
(f)
Media filter flush valve V36 (6) - closed.
(g)
Air backwash valve V22 (7) - partially open. Monitor air sys tem pressure and if it drops below 150 psig (1034 kPa)
before step 3 starts, close valve.
NOTE
Remember to adjust feed flow to 30 gpm (1 14 I/m) using the feed control valve.
(3)
Backwash step 3, water backwash (10 minutes).
(a)
Clean/flush outlet valve V5 (1) - closed.
(b)
Media filter inlet valve V16 (2) - closed.
(c)
Backwash inlet vale V15 (3) - open.
(d)
Backwash outlet valve V17 (4) - open.
(e)
Media filter outlet valve V35 (5) - closed.
(f)
Media filter flush valve V36 (6) - closed.
(g)
Air backwash valve V22 (7) - closed. (This is the only valve that changes position.)
NOTE
Remember to adjust feed flow to proper amount per Table 2-25 using the feed control valve.
(4)
Backwash step 4, clean water backwash (two minutes).
(a)
Clean/flush outlet valve V5 (1) - open. (This is the only valve that changes position.)
(b)
Media filter inlet valve V16 (2) - closed.
(c)
Backwash inlet valve V15 (3) - open.
(d)
Backwash outlet valve V17 (4) - open.
(e)
Media filter outlet valve V35 (5) - closed.
(f)
Media filter flush valve V36 (6) - closed.
(g)
Air backwash valve V22 (7) - closed.
(5)
Backwash step 5, media flush (after completion of backwash).
(a)
Clean/flush outlet valve V5 (1) - closed.
(b)
Media filter inlet valve V16 (2) - open.
(c)
Backwash inlet valve V15 (3) - closed.
(d)
Backwash outlet valve V17 (4) - closed.
(e)
Media filter outlet valve V35 (5) - open.
(f)
Media filter flush valve V36 (6) - open.
(g)
Air backwash valve V22 (7) - closed.
c.
Compete Manual Media Filter Backwash (Figure 2-77). This situation can occur if the backwash timing or control circuits fail
Shut down to standby and leave the OPERATION MODE switch (1) set to FILTER NORMAL. Use following procedure.
Change 12 2-159/(2-160 blank)
