Maintenance, Schedule – Xylem MM 318C 25A Make-up Water Feeders for Receiving Tanks User Manual
Page 2

MAINTENANCE
SCHEDULE:
• Blow down weekly during heating season. Blow
down may have to be more frequent depending on
local water conditions and the amount of make-up
water.
• Clean strainer at least twice during heating
season. Cleaning may have to be more frequent
depending on local water conditions and the
amount of make-up water.
• Replace control every 15 years.
PUMP
DISCHARGE
FEED PUMP
RECEIVER TANK
BLOW-OFF
VALVES
STRAINER
BASKET ASS’Y
OUT
CONDENSATE
RETURN
VENT
CHECK VALVE
BY PASS
3
/
4
’’ PIPE
IN
DISCHARGE
WATER SUPPLY
a. Follow the diagram to the right for piping the
feeder to the tank and water supply. Remember
to leave room for servicing the water feeder.
• The discharge piping should be connected to
the top of the tank. The height of the discharge
piping should be as short as possible and use
minimum amount of fittings.
• An air break can be used if code mandates one.
• There is not a positive seal between the valve
and the float chamber. If too much back
pressure is developed, the water from the
valve will go into the float chamber.
• At all right angle turns in the equalizing piping,
crosses should be used to facilitate inspection
and cleaning.
STEP 2 - Installation of Model 25A
Capacity Curve No. 25A
FEEDER DISCHARGE
WATER SUPPLY PRESSURE IN LBS. PER SQ. IN.
10,000
lbs./hr.
9,000
8,000
7,000
6,000
5,000
4,000
3,000
2,000
1,000
0
0
psi
10
20
30
40
50
60
70
80
90 100
(0)
(kg/cm
2
)
(.7) (1.4) (2.1) (2.8) (3.5) (4.2) (4.9) (5.6) (6.3) (7.0)
(4536)
11,000
(4990)
(kg/hr.)
(4082)
(3629)
(3175)
(2722)
(2268)
(1814)
(1361)
(907)
(454)
(0)
BOILER
22
20
18
16
14
12
10
8
6
4
2
0
(83.27)
(75.70)
(68.13)
(60.56)
(52.99)
(45.42)
(37.85)
(30.28)
(22.71)
(15.14)
(7.57)
(0)
gpm
(lpm)
319
290
261
232
203
174
145
116
87
58
29
0
(238)
(216)
(195)
(173)
(151)
(130)
(108)
(86)
(65)
(43)
(22)
(0)
hp
(Kilowatts)
M
ax
im
um
Ca
pa
cit
y
Xylem Inc.
8200 N. Austin Avenue
Morton Grove, Illinois 60053
Phone: (847) 966-3700
Fax: (847) 965-8379
www.xyleminc.com/brands/mcdonnellmiller
McDonnell & Miller is a trademark of Xylem Inc. or one of its subsidiaries.
© 2013 Xylem Inc. MM-318C July 2013 Part No. 246732