3
1"
The 42S and 42S-N controls are
installed so that the horizontal cast line
on the body is
1
a
a
” (35mm) below
the
boiler’s
normal
water level,
but not
lower than the lowest, safe permissi-
ble water level, as determined by the
boiler manufacturer.
The 42S-A controls are installed in boil-
er’s gauge glass tappings. The horizontal
cast line should be approximately
1” (25
mm) above
the bottom of the glass.
Verify that this level is
not below the
lowest, safe permissible water level,
as determined by the boiler manufac-
turer.
STEP 1 - Determine the Elevation at Which the
Low Water Cut-Off/Pump Controller Must be Installed
INSTALLATION –
TOOLS NEEDED:
Two (2) pipe wrenches, one (1) flathead screw
driver, and pipe sealing compound.
IMPORTANT:
Follow the boiler manufacturer's
instructions along with all applicable codes and
ordinances for piping, blow down valve and water
gauge glass requirements.
1
3
/
8
"
STEAM EQUALIZING PIPE
VERTICAL EQUALIZING PIPE
BLOW DOWN VALVE
NORMAL BOILER
WATER LINE
LOW WATER
CUT-OFF/PUMP CONTROLLER
BURNER CUT-OFF
LEVEL AT CAST LINE
LOWEST
PERMISSIBLE
WATER LEVEL
(35mm)
WATER
EQUALIZING
PIPE
STEAM EQUALIZING PIPE
VERTICAL EQUALIZING PIPE
BLOW DOWN VALVE
LOW WATER
CUT-OFF/PUMP CONTROLLER
BURNER CUT-OFF
LEVEL AT CAST LINE
WATER
EQUALIZING
PIPE
1
3
/
8
"
NORMAL BOILER
WATER LINE
LOWEST
PERMISSIBLE
WATER LEVEL
(35mm)
Series 42S
Series 42S-N
Summary of Contents for McDonnell & Miller 42S-N Series
Page 1: ...INSTRUCTION MANUAL MM 231G...
