Graco D Series Instructions Manual page 9

Check the tightness of the spray tip retaining nut (21).
Before each day's operation, lubricate the exposed
portion of the needle (22) and the piston (13) with a
lubricant compatible with the fluid to be sprayed. After
lubricating, cover the exposed portions of the needle
and piston with a piece of plastic to prevent fluid
build-up on these parts. Any spray build-up could
damage the valve packings (16 and 24). See Fig. 2.
Use a fluid filter to remove particles and sediment that
could cog the tip.
Set the actuating mechanism (timer) so that the gun
will start spraying before meeting the workpiece and
stop spraying just after the workpiece has passed.
14
15
16
18
21
Spray tip
23
(not included)
Fig. 2
Operation
Set the actuating air to at least 50 psi (345 kPa, 3.4
bar) and start the pump. Adjust the pump speed and
pressure to obtain the proper pump atomization –
always use the lowest pump speed necessary to get
the results you want. The spray tip orifice size and
angle determines coverage and pattern. Do not try to
get more coverage by increasing the pump pressure –
use a larger tip instead.
NOTE: In a circulating system, adjust the back pres-
sure valve to provide constant system back pressure
for all guns while maintaining the proper pressure for
fluid circulation. Refer to the Typical Installation on
page 6.
9
13
5
4
22
7
24
11
10
14
3
7
18
06375
13
22
06376
9
306830