Xylem 792 Instruction Manual

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Page 1

INSTRUCTION MANUAL

Model 792

High Pressure Water Vent Valve

HS-112

REVISION D

Hoffman Specialty

Model 792 High Pressure Water Vent Valve

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

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

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 instruction can result in personal injury from hot water and/or property damage.

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.

CAUTION

WARNING

• 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.

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.

CAUTION

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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.

1/2’’ EQUALIZING LINE WHERE LARGE AMOUNTS OF AIR

1/2’’ SAFETY DRAIN

MUST BE VENTED

1’’ MINIMUM

INSTALL SHUTOFF VALVES IN VERTICAL PIPE ONLY

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)

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)

1/2’’ SAFETY DRAIN

INSTALL SHUTOFF VALVES IN VERTICAL PIPE ONLY

STORAGE TANK

Note: Leave shut-off valves open for proper installation. Close only to service unit.

FIGURE 1

WARNING

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 contact with discharging fluids. Failure to follow this instruction 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 rupture. 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.

NOTE

HIGH POINT OF SYSTEM

FIGURE 2

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.

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

Xylem Inc.

8200 N. Austin Avenue Morton Grove, Illinois 60053 Phone: (847) 966-3700 Fax: (847) 965-8379 www.xyleminc.com/brands/bellgossett