Xylem MM 200G Series 64 Low water Cut-Offs - Manual (Page 2)

Gauge Glass Mounted
Directly into Boiler
CUT-OFF
LEVEL
1" BLOW DOWN
VALVE
For Boilers with
Independent Water Columns
1" STEAM
EQUALIZING PIPE
MODEL 64
LOW WATER
CUT-OFF
1" WATER
EQUALIZING PIPE
1" WATER
EQUALIZING PIPE
1" WATER
EQUALIZING PIPE
CUT-OFF
LEVEL
MODEL 64
LOW WATER
CUT-OFF
2
a. Whether the gauge glass is mounted directly into the boiler or on an independent water column, the
cut-off line on the 64 body casting should be mounted 1/2" (15mm) above the lowest visible point of the
gauge glass.
Test the Model 64 Before Leaving the Site
Open the blow-down valve, causing the water level to drop in the float chamber while burner is operating. As
the float drops the alarm circuit (if used) closes first; then on further drop the cut-off circuit will open, shut-
ting the burner off.
IMPORTANT: Instruct boiler attendant to blow down the float chamber at least once a week during the heating
season, if operating pressure is below 15 psi (1 kg/cm 2 ). If above 15 psi blow down once a day.
NOTE: On new boiler installations, leaky systems, or where the quality of the water is poor, blow down the
control more frequently.
a. Locate the gauge glass and
determine the level that the 64
has to be mounted at in order
to achieve the criteria in Step 1.
b. Pipe the 64 following the
diagrams shown to the right.
Follow the diagram that
represents your boiler.
c. Crosses should be used at
each right angle connection for
inspection and cleaning.
d. Make sure the blow-down
valves are full port.
STEP 2 - Installation of the Model 64
Model 64 – For Steam Boilers with 1” (25mm) Equalizing Lines
INSTALLATION –
TOOLS NEEDED:
One (1) flathead screwdriver and two (2) pipe wrenches.
Protect yourself when blowing down controls, hot water and steam will flow out of the drain pipe attached to the blow-down
valve. Failure to follow this caution may result in serious burns.
CAUTION
STEP 1 - Determine the Location of the Low Water Cut-Off