ITT Industries Bell & Gossett B-38 User manual

DESCRIPTION
The Bell & Gossett Pressure Reducing Valve is designed for
filling hot water boilers and associated piping systems to a
properly controlled pressure after boiler installation or sys-
tem servicing. It is not a safety device and is not intended
to be used as a water feed valve to control boiler water
at a safe operating level. They are factory set at specified
limits although adjustment is easily made. They are equipped
with a built-in strainer and low inlet pressure check valve.
SIZES & PERFORMANCE
Maximum Flow 51/2-6 GPM at 125 PSIG inlet Pressure.
TEMPERATURE AND PRESSURE LIMITS
Maximum Operating Temperature: 225°F.
Maximum Working Pressure: 125 PSIG
INSTALLATION INSTRUCTIONS
The Pressure Reducing Valve must be installed with the flow
arrow on the body pointing in the direction of flow. A shut-off
valve must be installed on the city water side of the Pressure
Reducing Valve. If the Pressure Reducing Valve is not
equipped with a fast fill feature, a by-pass may be used for
rapid filling, but it must remain closed during normal system
operation.
For safe boiler operation, installation of a low water cut off,
adequate burner safety control and a properly installed float
operated water feed control is recommended. Examples of
these types of control devices include the McDonnell & Miller
No. RB-24 and RB-120 low water cut offs and the No. 47-2
combination feeder and low water cut off.
Uncontrolled firing and overheating of boiler and boiler com-
ponents may occur in a hot water heating system that is
installed without adequate safety controls. The installation of
a functioning air control system and thermal expansion com-
pensation system is required for the proper operation of a
hot water heating system.
Bell & Gossett
V55999
REVISION L
INSTRUCTION MANUAL
Reducing Valves
Installation, Operation &
Service Instructions
INSTALLER: PLEASE LEAVE THIS MANUAL FOR THE OWNER’S USE.
Bell & Gossett
SAFETY
INSTRUCTIONS
This safety alert symbol will be used in this manual to
draw attention to safety related instructions. When used,
the safety alert symbol means ATTENTION! BECOME
ALERT! YOUR SAFETY IS INVOLVED! FAILURE TO FOL-
LOW THESE INSTRUCTIONS MAY RESULT IN A SAFETY
HAZARD.
WARNING LABEL
PART NO. V56871
INSTALLED IN THIS
LOCATION. IF MISSING
IT MUST BE REPLACED.
FACTORY ADJUSTABLE
MODEL SIZE SETTING RANGE
NUMBER INCHES PSIG PSIG
B-38
1
/ 2
NPT
B 7-12
3
/ 4
B-38TU
1
/ 2UNION
12 10-25
NPT/SWEAT
FB-38
1
/ 2 NPT
FB-38TU
1
/ 2UNION
NPT/SWEAT
6
1
/ 2
NPT 45 25-60
7
3
/ 4
RETURN
BOILER
VALVE
FLOW
C.W. FILL
B&G MODEL “B”
OR “DV” ASME TANK
VALVE
SHUT-OFF
B&G AUTOMATIC
B&G RELIEF
AIR VENT
OPTIONAL
SIDE OUTLET
BOILER
CONNECTION
TYPICAL INSTALLATION
B&G PRESSURE
REDUCING VALVE
B&G IN-LINE B&G
FLO-CONTROL
VALVE
TO
SYSTEM
B&G BOOSTER
AIR SEPARATOR

2
WARNING: Injecting cold water into a boiler that
has overheated due to uncontrolled firing and/or
improper water level control, can cause excessive stresses
in boiler components and possible rupture of the boiler.
This will be prevented by proper selection and installation of
a water level control and burner safety controls. The shut-
off valve at the pressure reducing valve inlet must be closed
except when filling the system, after installation, or after ser-
vice. Failure to follow these instructions could result in seri-
ous personal injury or death and property damage.
WARNING: Low pressure conditions may occur
during uncontrolled overfiring of the boiler. This
could result in cold water being added to an extremely
overheated boiler, causing excessive stress on boiler com-
ponents, and possible rupture of the boiler. The shut-off
valve, installed on the Reducing Valve inlet, must be kept
closed except during initial system fill, or when manually
adding water to the system because of a loss of pressure.
This will prevent water from being added to an overheated
boiler. NEVER ADD WATER TO AN OVERHEATED
BOILER. Failure to follow these instructions could result in
serious personal injury or death and property damage.
1. Pipe Reducing Valve into system as shown on typical
installation drawing on page 1.
2. When installing Reducing Valve models that include a
sweat union connection feature, first sweat the tailpiece in
place, then assemble union nut to Reducing Valve.
OPERATING INSTRUCTIONS
Model No’s. B-38, B-38TU and B7-12 are preset at 12 PSI,
and No’s. 6 and 7 are preset at 45 PSI. Open the cold water
fill valve to allow the system to fill until the preset pressure of
the valve has been obtained.
Model No’s. FB-38 and FB-38TU are preset at 12 PSI, and
are equipped with a fast fill lever. When filling the system, the
fast fill lever should be manually placed in the top vertical
position. This overrides the pressure regulating function
of the reducing valve. The system should be filled until the
boiler pressure gauge indicates the preset pressure of the
valve. The fast fill lever should then be placed in the horizon-
tal position for the normal automatic operation.
PRESSURE SETTING
The pressure setting can be changed by the following steps:
1. Allow water in heating system to cool to ambient tempera-
tures.
2. Reducing Valve pressure setting can be adjusted by loos-
ening the jam nut on top of the Reducing Valve and turning
the slotted adjusting screw. Turn the screw clockwise to
increase the set pressure, or counterclockwise to lower
the set pressure. This should be done slowly until the boiler
pressure gauge indicates the desired fill pressure.
NOTE: Do not adjust pressure to less than 10 psig.
3. Hold the adjusting screw stationary with a screwdriver
and tighten the jam nut.
4. Return the system to operation.
5. Close the cold water shut-off valve.
CAUTION: The use of Teflon impregnated pipe com-
pound and Teflon tape on pipe threads provides
lubricity which can lead to overtightening and breakage. Do
not overtighten. Failure to follow this instruction can result in
moderate personal injury from hot water and/or property
damage.
WARNING: Use of improper procedures to sweat
Reducing Valve models with union connection into
a system can damage the Reducing Valve. Before installing
sweat union connection to Reducing Valve, the union con-
nection must be first sweated (soldered) into place. Failure
to follow these instructions could result in serious per-
sonal injury or death and property damage.
WARNING: Improper use of fast fill feature can
result in over pressurization of the boiler system.
The fast fill lever must never be left in the upright position
after the system has been filled. The handle must be
placed in the horizontal position to avoid over pressuriza-
tion and unnecessary relief valve discharge. Damage to
the Reducing Valve and other system components can
result. Failure to follow these instructions could result in
serious personal injury or death and property damage.
CAUTION: The generous use of pipe joint compound
when installing Pressure Reducing Valve will foul the
valve operating mechanism, preventing it from functioning
properly. Pipe joint compound must be conservatively
applied to male threads only. Failure to follow this instruction
can result in moderate personal injury or property damage.
CAUTION: Corrosion and eventual failure of system
components can result from the constant addition of
fresh water. After the system has been filled, the cold water
shut-off valve must be closed. This will prevent system leaks
from being undetected by the constant replacement of lost
system water. Failure to follow these instructions could
result in property damage and/or moderate personal injury.
ADJUSTING SCREW
HEX. JAM NUT
SPRING CAP
SPRING
WARNING LABEL
(FAR SIDE)
NAME PLATE
(NEAR SIDE)
HEX. NUT
SPRING PLATE
COVER SCREWS
DIAPHRAGM
CHECK VALVE
VALVE PLATE
STEM
STEM ASM.
DISC
VALVE CUP
STRAINER
BODY
O-RING
STRAINER NUT
BODY COVER

SERVICE INSTRUCTIONS
1. One way to determine if the Pressure Reducing Valve is
working is to carefully place your hand on the Reducing
Valve body. If the system is up to temperature but the
valve body feels cold to the touch, then it is passing
water. The problem may be an improper setting (see
action on Pressure Setting), a leak downstream, or a faulty
valve (which would need to be replaced).
2. If the relief valve discharges periodically, it is an indication
that the system may have lost its air cushion in the com-
pression or expansion tank. To determine if this is the
case, initiate the following test:
a. Bladder or diaphragm style pre-charged tanks: Shut off
boiler and allow system to cool to ambient tempera-
ture. Isolate the tank from the system, then bleed the
water from the tank. Place a tire-type pressure gauge
on the air valve on the tank. If the pressure is zero, the
cushion is lost. The absence of the cushion may be
from a leaking air valve. To check if this is the case,
add some air to the tank and place some liquid on the
valve stem area. If the liquid bubbles, the valve is leak-
ing and must be replaced (see Instruction Manual
A01500 for valve replacement). If the absence of the air
cushion was not caused by a leaking valve, then the
bladder or diaphragm is leaking, and the bladder must
either be replaced (for the “B” Series) or the tank must
be replaced (for the “D” Series). See Instruction Manual
A01500 for bladder replacement.
b. Conventional compression tanks: Shut off the boiler for
approximately 30 minutes. Record the pressure. Turn
the boiler on. If, within 8-9 minutes, the pressure gauge
at the boiler indicates a value within 10% of the relief
valve setting, then the tank is waterlogged and needs
to be drained and re-charged (see Instruction Manual
S10300 for drain and air-charge procedures).
3. If the Pressure Reducing Valve fails to fill to the set COLD
fill pressure, the strainer may be clogged. To service the
strainer, follow the following steps:
a. Verify that the city water or cold water shut-off valve is
closed.
b. Turn the boiler on-off switch to the “OFF” position.
c. Remove strainer nut located on bottom of reducing
valve.
d. Remove and clean or replace the strainer.
e. Reinstall the strainer nut with O-ring into the reducing
valve and tighten to a torque of 10 in-lbs. Min. – 100 in-
lbs. Max. Replace the strainer nut with O-ring if it is
damaged.
f. Close the boiler drain and open cold water shut-off valve
to refill system.
g. After system has been filled and vented, turn the boiler
on-off switch to the “ON” position and resume normal
boiler operation. Close the cold water shut-off valve.
Valve Repair
To service the valve using the repair kit, follow steps 1, 2 and
3 from above and these additional steps:
d. Remove the strainer.
e. Using a size 25 Torx screwdriver, unfasten the six
cover screws and remove the body cover. (A 1/8" Allen
wrench will work in an emergency, but stripping may
occur).
f. Remove the spring cap and spring.
g. Remove the hex nut by holding the stem assembly sta-
tionary while turning the nut counterclockwise. The
stem assembly may drop once the nut has been
removed.
h. Lift off the spring plate, diaphragm and valve plate.
i. Pull the rubber check valve from the valve body and
replace.
j. Insert new stem assembly into valve body through the
strainer opening in the housing. Hold in place.
k. Place the new valve plate, knob side down, on the
stem assembly.
l. Set new diaphragm on top of the stem, aligning holes
with those in the body.
m. Place spring plate over the diaphragm on top of the
stem assembly.
n. Thread the hex nut on the stem assembly. A dab of
Loctite (IMPORTANT! Any more than a dab will seize
the valve!) must be added to the hex nut before thread-
ing on the stem.
o. Place spring, spring cap and body cover on top.
p. Align body cover holes with those in the body and fas-
ten body cover screws.
q. Reinstall the strainer nut with O-ring into the reducing
valve and tighten to a torque of 10 in-lbs. Min. – 100 in-
lbs. Max. Replace the strainer nut with O-ring if it is
damaged.
r. Close the boiler drain and open cold water shut-off
valve to refill system.
s. After system has been filled and vented, turn the boiler
on/off switch to the “ON” position and resume normal
boiler operation. If pressure setting differs from previ-
ous setting, refer to section on pressure setting. Close
cold water shut-off valve.
WARNING: System fluid under pressure and/or at
high temperatures can be very hazardous. Before
servicing, reduce system pressure to zero or isolate the
pressure reducing valve from the system. Leave drain
valve open. Allow system to cool below 100°F. Failure to
follow these instructions could result in serious personal
injury or death and property damage.
WARNING: Do not use teflon tape when installing
the strainer nut with O-ring. The teflon tape provides
lubricity which can lead to overtightening and breakage.
Do not overtighten. Failure to follow these instructions
can result in moderate personal injury from hot water
and/or property damage.
WARNING: Corrosion or leakage are indications
that the Pressure Reducing Valve may be about to
cause serious damage from leakage or rupture. It must be
periodically inspected and if corrosion or leakage is noted,
the pressure reducing valve must be serviced or replaced.
Failure to follow these instructions could result in serious
personal injury or death and property damage.
3
WARNING: Do not use teflon tape when installing
the strainer nut with O-ring. The teflon tape provides
lubricity which can lead to overtightening and breakage.
Do not overtighten. Failure to follow these instructions
can result in moderate personal injury from hot water
and/or property damage.