GAS PIPING
Route the gas piping or tubing to the furnace. Use th"
black iron pipe or %" O.D. copper tubing If the piping
length exceeds 40', use 't7^" black iron pipe or '/a" copper
tubing.
When using natural gas, branch tubing may be copper
internally tinned or copper tubing containing not more
than 75 percent copper. When using L.P. gas, tubing
may be type K. Be sure to check local authorities for
any other requirements concerning gas piping. It is
recommended that a main shut-off valve be located in
the gas supply line external to the furnace. This shut-
off valve is required by AGA as well as some local
codes.
When making the connection at the gas control valve,
use a wrench on the inlet side to prevent twisting the
valve body which could result in service problems.
After connections have been made, be sure all joints
are checked with soap suds to detect any leaks. This
should also include a check of the furnace controls
and piping. NEVER CHECK FOR LEAKS WITH
A LIGHTED MATCH.
CAUTION: DO NOT TEST THE FUEL SYSTEM AT
MORE THAN 14 INCHES WATER COLUMN AFTER
FURNACE HAS BEEN CONNECTED TO FUEL LINE.
ANY TEST CONDUCTED ABOVE 14 INCHES WATER
COLUMN MAY DAMAGE THE FURNACE CONTROL
VALVE AND VOID THE WARRANTY.
DESCRIPTION
The B57 Midgitrol (Coleman Part No. 7660-3261) is a
combination gas valve which provides all manual and
automatic control functions required for operation of
gas fired heating equipment. This valve is suitable for
use with all gases.
The B5l includes (l) permanently lubricated shear
seal, disc type gas cock, (2) thermomagnet safety
valve, (3) main line automatic valve, (4) pilot gas adjust-
ment valve, and (5) pilot line filter and pressure regu-
lator (optional).
OPERATION
The l00\a shut-off pilot safety section operates from
power bY a 2500G tYPe thermo-
couple d bY Pilot flame. In event
of low outage, safetY valve shuts
off all gas.
Main line automatic gas valve opens and closes in re-
sponse to thermostat or other controls wired in 24 volt
circuit. 24 voitt power is provided by an external
transformer.
INSTALLATION
Use valve within following operating ranges:
Maximum operating pressure: t/z psi (14" WC)
Minimum operating pressure: I oz. (2" WC)
Maximum ambient temperature: 175"F.
l. Valves with Part No. 7660-326 I are step open type
and must be mounted upright in horiz.ontal line.
INSTALLATION INSTRUCTIONS
2. Make sure all piping and tubing is free of foreign
matter. Apply thread seal to male threads only.
3. Connect t7r" pilot tubing bween valve and pilot
burner assembly. Pilot burner assembly m ust be
mounted rigidly in a position where pilot will ignite
main burner when it has been reduced to smallest
flame which will hold thermomagnet safety' valve open.
4. t/,s" external vent connection is located at outlet end
of valve. Connect one end of vent tube to fitting on
valve and position other end near, . but not in, pilot
flame. Main burner flame must not impinge on gen-
erator cartridge or vent tube.
5. Make sure all wiring connections are clean and tight.
Screw thermocouple bushing in fingertight, plus I
turn. with small wrench. DO NOT OVERTIGHTEN.
6. Refer to information furnished with furnace for
proper heat anticipator sctting.
LIGHTING/ RESET
DIAL
EXTERNAL
VENT
CONN
MANI FOLD
PRESS. TAP
PI LOT
GAS
CONN. Figure 3.
LIGHTING PROCEDURE
l. Turn thermostat to lowest selting.
Turn to PILOT. Press dial in and
light pilot. Hold for 60 seconds and
release.
2. Turn dial counterclockwise to ON.
Use this position for thermostat
control. Set thermostat for desired
room temperature.
3. Shut Down Procedure. Press dial
in and turn clockwise to OFF. Use
this position when complete shut-
down is necessary. (Use PILOT
position lor temporary or seasonal
shutdown.)
ADJUSTMENTS See Fig.3 for Location-
Pilot Cas Adjustment. Remove pilot adjustment cap
screw and turn pilot adjustment screw to produce non-
blowing blue flame covering top t7o" of thermocouple
tip. Replace cap screw.
