Graco LineLazer IV 250SPS Installation And Operation Manual page 24

Operation
Determining Bead Application Pressure
The table below lists bead delivery rates for 4 inch
(10 cm) lines with standard size highway beads.
• Wider lines use multiples of 4 in. to determine bead
delivery.
• Larger beads reduce flow rates, so a larger nozzle
and higher pressure may be required.
• Always verify flow rates with a stopwatch and a
scale for weight.
To determine application pressure, follow steps 1 - 4
below:
1. Determine speed the machine will travel when
applying line.
Step 1
Bead Delivery Requirement (4 in.)
Speed
6 lb/gal
mph lb/min
2 3.6
3 5.3
4 † 7.1
5 8.9
6 10.7
7 12.4
8 14.2
Step 1
Bead Delivery Requirement (10 cm)
Speed
720 gram/liter
mph lb/min
2 3.6
3 5.3
4 † 7.1
5 8.9
6 10.7
7 12.4
8 14.2
24
Step 2
8 lb/gal
lb/min
4.7
7.1
9.5
11.9
14.2
16.6
19
Step 2
960 gram/liter
lb/min
4.7
7.1
9.5
11.9
14.2
16.6
19
2. Identify what the required bead delivery rate is in job
specifications.
3. Under bead gun nozzle size, find nearest value
compared to Step 2.
4. Match pressure needed to Step 3. Set air regulator
to this pressure.
† EXAMPLE:
a. At 4 mph and 6 lb/gal with 0.234 nozzle set tank
pressure to 15 psi.
b. At 4 mph and 6 lb/gal with 0.281 nozzle set tank
pressure to psi.
c. For 8 in. width, multiply weight/min value
(7.1) x 2 and for 12 in. width x 3.
Step 3
Nozzle Size
0.234 0.281
lb/min lb/min
4 5
6 † 7
† 7 9
9 11
11 14
13 16
16 19
Step 3
Nozzle Size
0.234 0.281
lb/min lb/min
4 5
6 † 7
† 7 9
9 11
11 14
13 16
16 19
Step 4
Pressure Needed
psi
5
10
15
20
25
30
35
Step 4
Pressure Needed
psi
5
10
15
20
25
30
35
332230G