Bell and Gossett DB-3/4 Installation, Operation & Service Instructions

Installation, Operation, & Service Instructions
INSTALLER PLE SE LE VE THIS M NU L FOR THE OWNER'S USE.
NOTE: This product is not intended for use in potable
water applications.
S FETY
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 TTENTION! BECOME
S FETY IS INVOLVED! F ILURE TO FOLLOW THESE
INSTRUCTIONS M Y RESULT IN
DESCRIPTION
The Bell & Gossett DB differential by-pass valve is used in
systems where various heating loads may be simultaneously
excluded from the circuit because of the closing of control or
zone valves.
It ensures a recirculation proportional to the number of valves
which close, avoiding noises and maintaining the head of the
pump at a constant value.
DB-3/4"
Differential By-Pass Valve
3/4" x 3/4" NPT Male Connections
Operational Limits
Max. Temperature
Max. Pressure
LERT! YOUR
S FETY H Z RD.
Bell & Gossett
Instruction Manual 91590
230°F (110°C)
150psig (10 Bar)
TECHNIC L SPECIFIC TIONS
Connections:
Materials: – Body
– Seals
– Spring
– Knob
Medium:
Maximum Working Pressure:
Maximum Working Temperature:
Maximum Flow Rate:
djustment Range:
INST LL TION INSTRUCTIONS
C UTION: ll work must be performed by qualified
personnel trained in the proper application, installation,
and maintenance of systems in accordance with all applica-
ble codes and ordinances.
W RNING: System fluids are under pressure or temp-
erature can be hazardous. Be sure the pressure has
been reduced to zero and the system temperature is below
100°F (38°C). Failure to follow these instructions could result
in property damage and/or personal injury.
W RNING: State of California Residents
This product contains a chemical known by the State
of California to cause cancer. This products contains a
chemical known by the State of California to cause birth
defects or other reproductive harm.
REVISION
3/4" x 3/4" NPT Male
Stainless Steel
Water and glycol solutions up to 50%
150 PSI (10 Bar)
230°F (110°C)
2 to 10 PSI (0.15 to 0.7 Bar)
Brass
EPDM
BS
9 GPM