Xylem MM 200G Series 64 Low water Cut-Offs - Manual (Page 5)

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a. Remove gauge glass and its trim from the boiler.
Model 64-A – For Steam Boilers Using Quick Hook-up Fittings
INSTALLATION –
TOOLS NEEDED:
One (1) flathead screwdriver, two (2) pipe wrenches, and an adjustable wrench.
STEP 1 - Preparing the Boiler
a. See figures 1 and 2. Install both brass Y fittings
(A) into the boiler gauge glass tappings.
NOTE: If gauge glass tappings are spaced
more than 10 1/8" (270mm) apart, invert the
Black Y (B). See figure 2. If spaced greater
than 13 3/8" (339mm), substitute a longer
1/2" (15mm) nipple for original (C).
b. See figure 3. Install reducing bushing (D) and
nipple (C) into top 1" (25mm) NPT tapping (E).
Install reducing bushing (F), nipple (G), and
blow down valve (H) into 1" (25mm) NPT (J).
c. See figure 3. Slip union nut (K) over lower tail
piece (L) and screw it into either 1/2" (15mm)
tapping (M) or (N). Use the 1/2" (15mm) pipe
plug to close unused tapping. Slip union nut (O)
over union piece (P) and nipple (R) and install
into black Y (B). Slide black Y (B) over nipple
(C). Connect upper (O) and lower (K) unions to
brass Y fitting (A, figure 1) and tighten.
NOTE:
the black Y (B) will have to be moved up or
down to mate the union halves. Tighten
compression nut (S).
STEP 2 - Installation of the Model 64-A
Test the Model 64-A Before Leaving the Site
While the burner is operating open the blow-down valve, causing the water level to drop in the float chamber.
As the float drops the alarm circuit (if used) closes first; then on further drop the cut-off circuit will open,
shutting the burner off. NOTE: If no Test-N-Checks (TC-4) valves were used, do this test before filling the
system completely.
IMPORTANT: Instruct boiler attendant to blow down the float chamber at least once a week during the heat-
ing season, if operating pressure is below 15 psi (1 kg/cm 2 ). If above 15 psi blow down once a day.
NOTE: On a new boiler installation, leaky system, or where the quality of the water is poor, blow down the
control more frequently.
Protect yourself when blowing down controls, hot water will flow out of the drain pipe attached to the blow-down valve.
Failure to follow this caution may result in serious burns.
CAUTION
A
C
B
INVERTED
H
G
D
E
F
B
S
P
M
J
O
R
L
K
N
C
Figure 1
Figure 2
Figure 3