Xylem Inc.
8200 N. Austin Avenue
Morton Grove, Illinois 60053
Phone: (847) 966-3700
Fax: (847) 965-8379
www.xyleminc.com/brands/bellgossett
Bell & Gossett is a trademark of Xylem Inc. or one of its subsidiaries.
© 2013 Xylem Inc. HS-112D February 2013 Part No. 512725
INSTALLATION
An equalizing line is recommended for continuous
operation applications as with water storage tanks.
See Figure 1.
The Hoffman No. 792 Water Vent should always
be installed with a safety drain from the discharge
port to a suitable waste. At high rates of discharge
at pressure, a fine mist will be discharged with the
air. If dirt lodges between valve pin and seat, the
valve will not close properly and water will be
discharged at system pressure until problem is
corrected.
Model 792 Capacity
Water Pressure
Air Discharge to Atmosphere
psig (bar)
CFM (M
3
/min.)
100
(6.9)
10
(.28)
150
(10.3)
15
(.42)
200
(13.8)
20
(.57)
250
(17.3)
25
(.70)
Temperature and Pressure Limits
Maximum Temperature: 300˚F (149˚C)
Maximum Operating Pressure: 250 psig (17.3 bar)
Maximum Hydrostatic Pressure: 350 psig (24.2 bar)
1/2’’ EQUALIZING LINE WHERE
LARGE AMOUNTS OF AIR
MUST BE VENTED
1/2’’ SAFETY
DRAIN
1’’ MINIMUM
STORAGE TANK
INSTALL SHUTOFF VALVES
IN VERTICAL PIPE ONLY
FIGURE 1
1/2’’ SAFETY
DRAIN
HIGH POINT OF SYSTEM
FIGURE 2
INSTALL SHUTOFF VALVES
IN VERTICAL PIPE ONLY
Note: Leave shut-off valves open
for proper installation. Close only
to service unit.
NOTE
The air vent will discharge air and possibly some liquid
during its normal functioning. Avoid eye, face or skin
contact with top area of air vent. We recommend the vent
connection be piped to a drain to prevent accidental con-
tact with discharging fluids. Failure to follow this instruc-
tion can result in serious personal injury and/or property
damage.
!
WARNING
Corrosion or leakage are indications that the air vent may
be about to cause serious damage from leakage or rup-
ture. It should be periodically inspected and if noted, air
vent must be replaced or serviced. Failure to follow this
instruction can result in serious personal injury and/or
property damage.
!
WARNING
System fluid under pressure and/or at high temperatures
can be very hazardous. Before servicing, reduce system
pressure to zero or isolate the air vent from the system.
Allow system to cool below 100˚F. Failure to follow this
instruction can result in serious personal injury and/or
property damage.
!
WARNING
Model 792
High Pressure Water
Vent Valve (complete unit) . . . . . . . . . . . . 401494
Service Parts Available
Cover Gasket Part No.. . . . . . . . . . . . . . . . . 601273
Internal Parts Kit Part No. . . . . . . . . . . . . . . 600204
(includes cover gasket, pin, seat, lever arm, yoke,
cotter pin and integral connecting hardware)
Float . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600247
