Graco Inc 308741N dimensions Troubleshooting, Problem Cause Solution

Page 17

Troubleshooting

WARNING

PRESSURIZED EQUIPMENT HAZARD

To reduce the risk of a serious injury, follow the Pres- sure Relief Procedure on page 12 before checking or repairing any part of the gun or system.

PROBLEM

CAUSE

SOLUTION

 

 

 

 

Fluid flow is fluttering while spraying

1.

Fluid nozzle not tight enough

1. Tighten fluid nozzle to 125–135

 

 

 

in-lb (14–15 NSm).

 

2.

Fluid filter clogged

3. Check fluid filter.

 

4. Fluid adjustment knob not prop-

5. Turn the fluid adjustment knob

 

 

erly set

out for less feathering or use a

 

 

 

larger size nozzle.

 

 

 

Fluid flow fades while spraying high

1. Air hose size is too restricted for

1. Use 5/16 in. (7.9 mm) I.D. air

viscosity fluids

 

higher air flow being used

hose if the hose is 25 ft.

 

 

 

(7.625 m) long. If longer hose is

 

 

 

needed, use a 3/8 in. (9.5 mm)

 

 

 

I.D. hose.

 

2. Fluid pressure too low, causing

3. Raise fluid pressure at source or

 

 

fluid flow to reduce when gun is

use a smaller fluid nozzle.

 

 

elevated

 

 

 

 

Pattern becomes off-set or heavy on

Air cap horn holes plugged or dam-

Clean air cap horn holes with non-

ends

aged

metallic item such as a toothpick, or

 

 

 

replace air cap.

 

 

 

Gun fluid pressure is too high with

Using needle/nozzle kit with too

Use needle/nozzle kit with larger

gun triggered

small orifice

orifice

 

 

 

Using a low fluid pressure setting,

Using needle/nozzle kit with too

Use needle/nozzle kit with smaller

the fluid flow is too high, making it

large orifice

orifice

necessary to restrict needle travel to

 

 

 

reduce fluid flow

 

 

 

 

 

 

Fluid system will not operate at low

There is no fluid regulator, or air

Add low pressure fluid regulator, or

enough fluid pressure [below 10 psi

regulator on pressure pot is not sen-

add more sensitive low pressure air

(70 kPa, 0.7 bar)]

sitive enough at low pressures

regulator on pressure pot.

 

 

 

 

308741 17

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Contents Table of Contents Instructions Parts List308741 SymbolsPressurized Equipment Hazard Hvlp Spray Gun Assemblies Selection ChartsHvlp Spray Gun and Gravity Cup Hvlp Spray Gun and Pressure Cup AssembliesAssemblies Optional Hvlp Air CapsAtomizing Air Pressure Air Flow and Atomizing PressureAir Flow Ventilate the Spray Booth Typical InstallationConnect the Fluid Hose SetupConnect the Air Line Relieve the Pressure Position the Air Cap Adjust the Spray PatternFlush the Spray Gun Fluid Velocity of Fluid Nozzles At the Same Flow Rate Inch 7.9 mm I.D. hose Pressure Drop ChartAir Regulator Pressure Gun Inlet Pressure Setting Applying the Fluid Pressure Relief ProcedureOperation Do not immerse the gun in solvent Daily Gun Care, Flushing, and CleaningGeneral System Maintenance 7035A 7044A 7045A Lubricate Problem Cause Solution TroubleshootingFluid Packings Replacement ServiceItems Needed for Service 2b 2a Complete Gun Packing Replacement 20 or 25b 19 or 25a Service 308741 Item 13 includes item 13a Item 25 includes 25a-25d PartsItem 2 includes 2a-2b Description Qty Part No to Pressure Feed Hvlp Spray Gun AssemblyGun Needle Nozzle Kit Item 12 Nozzle Needle Assy7585A Gravity Feed Hvlp Spray Gun Assembly Accessories Gravity Cup Holder Bracket Gravity CupSST Pressure Cup Kit 239802 with single air regulator Quart Remote SST Pressure CupCategory Data DimensionsTechnical Data 308741 Toll Free Graco Standard WarrantyGraco Information