Graco Optimiser 2K 02748 Instructions Manual page 4

Includes:
Needle/
Nozzle/Air
Cap Kit Assembly
P/N
949–276 238–703
949–277 238–703
949–278 238–703
949–279 238–217
949–280
238–218
949–281 238–219
949–282 238–220
Selecting a Needle/Nozzle/Air Cap Kit
The kits range in size to provide different fluid flow
rates.
Use the fluid nozzle that will give the required flow
with the fluid adjustment knob opened four full turns
counterclockwise and an adhesive pressure of
approximately 5 to 20 psi (0.35 to 1.4 bar).
For low flow rates or light viscosity fluid, select the
smaller nozzle sizes.
For high flow rates or high viscosity fluid, select the
larger nozzle sizes.
Using an air cap size that is smaller than the
nozzle/needle size is not recommended.
To help select the proper needle/nozzle size, a fluid
pressure gauge may be connected temporarily to
the gun fluid inlet to determine the fluid pressure.
See Service to install the parts.
Selection Chart
Needle
Air Cap
P/N P/N
185–794
185–794
185–794
185–794
185–794
185–795
185–796
Replacement
Nozzle Needle Tip
P/N P/N
185–756 191–564
185–757 191–564
185–700 191–564
185–701 191–016
185–702 191–017
185–703 191–018
185–704 191–019
Selection Problems and Solutions
PROBLEM
Fluid pressure
required to achieve
flow rate is too high
Using a low pres-
sure setting, the
fluid flow is too high,
making it necessary
to restrict needle
travel to reduce fluid
flow
Fluid system will not
operate at low
enough fluid pres-
sure
Orifice Size
0.020" (0.508 mm)
0.026" (0.660 mm)
0.030" (0.762 mm)
0.042" (1.067 mm)
0.055" (1.397 mm)
0.070" (1.778 mm)
0.086" (2.184 mm)
POSSIBLE SOLUTION
CAUSE
Using set with Use needle/
too small of an nozzle/air cap
orifice set with larger
orifice
Using set with Use needle/
too large of an nozzle/air cap
orifice set with small-
er orifice
Fluid regulator is Add low pres-
not installed or sure fluid regu-
air regulator is lator or add
not sensitive more sensitive
enough air regulator on
pressure pot