Xylem Hoffman Specialty 792 User manual

INSTRUCTION MANUAL
HS-112
REVISION D
• Before using product, read and understand instructions.
• Save these instructions for future reference.
• All work must be performed by qualified personnel trained in the proper application,
installation, and maintenance of systems in accordance with all applicable codes
and ordinances.
• To prevent serious burns, wear heat resistant gloves when opening and closing supply
valves, or handling hot equipment.
• To prevent serious burns, the internal pressure of the system must be 0 psi (0 bar) before
servicing.
Failure to follow these cautions will cause personal injury.
Model 792
High Pressure Water Vent Valve
IMPORTANT: To prevent system damage from water
hammer or sudden shock, open supply valves slowly.
If you are uncertain about the product’s adaptability for
your application, please call the factory or authorized
representative before using the product.
The vent pressure rating must be equal or greater than
the maximum system pressure.
The vent discharge must be connected to a drain or fluid
recovery unit to prevent damage to the equipment or
structures in the event of leakage.
WARNINGCAUTION
CAUTION
!
Excessive use of pipe joint compound when installing air vent will foul
the vent’s operating mechanism allowing water to escape. Pipe joint
compound must be conservatively applied to male threads only. Failure
to follow this instruction can result in personal injury from hot water
and/or property damage.
!
CAUTION
When the vent discharges air or if foreign material from the system
fouls the vent’s operating mechanism, it is possible for water to also be
discharged. Vent must be piped to a drain. Failure to follow this instruc-
tion can result in personal injury from hot water and/or property damage.
!
CAUTION
The use of PTFE impregnated pipe compound and PTFE tape on pipe
threads provide lubricity which can lead to overtightening and breakage.
Do not overtighten. Failure to follow this instruction can result in
personal injury from hot water and/or property damage.
!
CAUTION
Hoffman Specialty®
Model 792
High Pressure Water Vent Valve

Xylem Inc.
8200 N. Austin Avenue
Morton Grove, Illinois 60053
Phone: [phone]
Fax: [phone]
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 (M3/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