Graco 332093A User Manual
Instructions
Dispense Valve
100psi (0.69 MPa, 6.9 bar) Maximum Working Pressure
Important Safety Instructions
Read all warnings and instructions in this manual.
Save these instructions.
See Page 3 for model information, including maximum
working pressure and approvals.
332093A
EN
Dispensit
Usage Statement – Depending on valve configuration this valve can be used to dispense the following:
Wide range of water-thin to medium viscosity material.
- 702-20
DISPENSIT® MODEL 702-20
DISPENSE VALVE
OPERATING & MAINTENANCE MANUAL
General Information ...................................................................................3
Safety Information ......................................................................................3
Illustration References ...............................................................................3
General Accessories ..................................................................................3
Description Of Operation ...........................................................................4
SetUp Procedure ........................................................................................4
Mounting Dispense Valve ..........................................................................4
Air Controller ..............................................................................................4
Operating Procedures ................................................................................5
Dry System Checkout ...............................................................................5
Material Loading .......................................................................................5
Remote Mounted Material Supply .........................................................5
Valve Mounted Syringe Material Supply ................................................5
Wet System Checkout .............................................................................6
Periodic Maintenance .................................................................................6
Dispense Needle Replacement ...............................................................6
Dispense Tube Replacement ..................................................................7
Disassembly ............................................................................................8
Model 702-20 General Illustration ............................................................9
Assembly .................................................................................................10
Troubleshooting .........................................................................................11
Model 702-20 Recommended Spare Parts................................................12
General Guidelines for O-rings and U-cup Seals .....................................13
Warranty ......................................................................................................14
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GENERAL INFORMATION
The Model 702-20 Dispense Valve is designed for applications that require ON/OFF dispensing of beads
and/or dots. It has dispensing capability for material viscosities ranging from water-type material to high
viscosity epoxies and metal filled pastes. This valve also has a fail-safe design to prevent material dumping in case of a power failure. All wetted parts are disposable for easy maintenance and cleaning. The
702-20 ships complete with the following:
Model 702-20 Dispense Valve
One 3 foot (.9 m) section of pneumatic air line
One package of replacement dispense tubes (type as ordered)
Seal Kit
Operating and Maintenance Manual
Syringe (comes with syringe option)
Optional syringe clamp (comes with syringe option)
Receiver Cap with air lines (comes with syringe option)
SAFETY INFORMATION
This product should be used only by employees who have been given appropriate training and safety
warnings as set forth in this manual. Read completely before operating.
Warning: Do not exceed 6.9 bar (100 psi) pressure on the operating system or 4.1 bar (60 psi) pressure
on the syringe reservoir. Higher pressures are not required and may cause a serious hazard.
Toxicity and flammability hazards depend upon the product being dispensed by this unit, and the user
should take appropriate safety precautions as indicated on the MSDS of the product.
Always wear safety glasses.
ILLUSTRATION REFERENCES
Throughout this manual you will find references by illustration item number to the illustrations in the
manual. The references are indicated by parentheses around a number such as: (7). Illustrations
represent typical valve configurations. The drawings for your exact model are inserted at the back of the
manual and include the part numbers for ordering replacement parts.
GENERAL ACCESSORIES
Graco Inc. offers a full line of standard and custom accessories for your dispensing needs including:
Valve Controllers
Syringe Feed Systems
Cartridge Retainers and Pressure Reservoirs
Transfer Pump Feed Systems for 1, 5 and 55 gallon containers
Mounting Bases and Brackets
Consult your Dispensit dealer or the factory for details.
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DESCRIPTION OF OPERATION
1. The normal ready state of the system is as follows:
The syringe or remote reservoir contains the dispensable material.
The system has been purged, filling the dispense tube and needle with material.
The Pinch-off Piston (18) is not pressurized, but is held back by the Spring (7) closing the
Dispense Tube (21) and holding back the dispensable material.
2. The dispense cycle begins when the controller is activated.
3. The Pinch-off Piston (18) moves forward to release the dispense tube allowing material to flow.
4. To complete the dispense cycle, the Pinch-off Piston (18) is pushed back by the Spring (7), sealing
the dispense tube to prevent material drip. The system is again in the normal ready state.
SETUP PROCEDURE
MOUNTING DISPENSE VALVE
For optimum operation, the Model 702-20 Dispense Valve must be mounted on a 1/2 inch (12.7 mm)
support rod post or frame. When mounting, affix the valve firmly in place by tightening the socket head
cap screw (4) with a 5/32 inch Allen wrench. Depending on the application, the valve may be tilted to a
maximum of 600 from the vertical.
AIR CONTROLLER
Operation of the Model 702-20 Dispense Valve requires a controller that can provide the following:
A minimum of 0.5 SCFM (2.3 cm3) of dry, unlubricated air at a minimum pressure of 4.8 bar (70 psi)
and a maximum of 6.9 bar (100 psi).
Time delay capability to allow the valve to cycle.
Independent air pressure regulators for material reservoir and valve operation.
“Purge capability” which is the ability for the operator to pass or not pass air to the pinch-off piston
(18) on the dispense valve.
For semiautomatic or automatic applications, a foot switch or other control to cycle the valve.
Connection for .16” ID x .25” OD(6.35mm) pressure tubing for use between the dispense valve and
controller.
Connection for .16” ID x .25” OD(6.35mm) pressure tubing for use between the controller and syringe.
NOTE: The syringe air supply must be regulated to a maximum of 4.1bar (60 psi).
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OPERATING PROCEDURES
DRY SYSTEM CHECKOUT
This is an initial checkout to determine if the setup has been properly completed.
Conduct the dry system checkout without any material in the system.
1. Attach the color-coded pneumatic pressure line from the fitting (6) to the color-coded cycle air outlet
on the air supply controller.
2. Turn on the electric and air supply.
3. Set the air pressure to 4.8 bar (70 psi) on the system pressure gauge.
4. In the normal rest position the pinch-off piston (18) is held back by the spring (7), sealing the dispense
tube(21).
5. Momentarily press the dispense valve cycling control switch. The pinch-off piston (18) is pressurized
to release the dispense tube. The controller dispense valve air solenoid valve should cycle and cause
a slight fluctuation in the system pressure gauge. When this happens, the system is correctly
installed.
MATERIAL LOADING
REMOTE MOUNTED MATERIAL SUPPLY
If the material supply is remote mounted then connect material supply tubing to the Dispense Valve
material inlet luer lock fitting. When using a remote reservoir, the material supply tubing and fittings must
be compatible with the material being dispensed and be capable of withstanding the dispensing pressure.
VALVE MOUNTED SYRINGE MATERIAL SUPPLY
1. Place the filled syringe of material through the syringe clamp, mating the syringe to the male luer lock
fitting on the dispense tube, turning until snug (do not over tighten).
2. Hand tighten the syringe clamp using the adjustment knob until snug.
3. Install the receiver cap assembly to the top of the syringe.
4. Attach the air line to the regulator and set the air pressure control to 1.0 bar (15 psi) or to the setting
required for the application.
WARNING: Do not exceed 6.9 bar (100 psi) pressure on the operating system or 4.1 bar (60 psi)
pressure on the syringe reservoir. Higher pressures are not required and may cause a serious hazard.
WARNING: Do not apply either operating or reservoir air pressure to the product unless all screws are in
place and properly tightened, and the receiver cap and/or reservoir lid is properly in place and tightened.
All air connections should be fastened securely.
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