Tweco PAK 10 - Manual (Page 24)

Operation 12 Manual No. 0-0515
Starting Pierce Continue Cut After Pierce
A-01920
Figures 3-F and 3-G Piercing with Hand Torch
When using a hand torch, tip the torch slightly to pierce
so that blowback particles blow away from the torch
tip rather than directly into it, as shown in Figure 3-F.
Pierce off the cutting line and then continue the cut as
shown in Figure 3-G. Spatter and scale should be
cleaned from the shield cup and the tip as soon as pos-
sible. Spraying or dipping the shield cup in anti-spat-
ter compound will minimize the amount of scale which
adheres to it.
NOTE
The suggestions listed below should be followed
in all cutting operations.
1. Wait five minutes before opening the main discon-
nect switch at shut down. This permits the cooling
fan to run to remove operating heat from the unit.
2. For maximum parts life, do not operate the pilot
arc any longer than necessary.
3. Remember that cutting current can be adjusted at
any time. Learn to change the current output to
provide a comfortable working speed for the par-
ticular material being cut.
4. Handle torch leads carefully and protect them from
damage.
5. In continuous cutting applications, it is often neces-
sary to manifold 4 to 6 C0
2
cylinders together to
maintain pressure at 50 psi (3.4 bar).
6. Because of the swirl of plasma gas in the torch, the
right hand side of the cut (in relation to torch travel)
is normally of better quality. Reverse swirl tips are
available for mirror image cutting.
FREQUENTLY REVIEW THE SAFETY PRECAU-
TIONS GIVEN AT THE FRONT OF THIS MANUAL.
WARNING
It is not enough to simply move the ON/OFF
switch on the unit to its OFF position when cut-
ting operations have been completed. Always
open the power supply disconnect switch 5 min-
utes after the last cut is made.
COMMON CUTTING FAULTS
Listed below are common cutting problems followed
by probable causes of each. If problems are caused by
the PAK 10, refer to the Trouble Shooting Section (Sec-
tion 4).
1. Insufficient Penetration
a. Cutting speed too high
b. Current too low
2. Main Arc Extinguishes
a. Cutting speed too low
b. Standoff too high
3. Dross Formation
a. Improper gas pressure or mixture
b. Improper cutting speed (Refer to Table 3-B)
c. Faulty electrode or tip
4. Burned-Out Tips
a. High cutting current
b. Damaged or loose cutting tip
c. Contact with work
d. Heavy spatter
e. Low plasma gas pressure
f. Back cap not tight
g. Spring not correctly installed