Advertisement
Available languages
Available languages
being spread on nozzle (see picture4). This operation
should be carried out with material thickness above
1/8" (3 mm). If you have to cut near angles or recesses
(see picture 5) it is recommended to use extended
electrodes and nozzles. Should circular cut be done it
is recommended to use caliper (supplied on request).
N.B. : Avoid keeping pilot arc uselessly on, in air to
avoid electrode, diffuser and nozzle consumption.
3.4 Cutting trouble
1) Insufficient penetration.
This may be due to:
high speed. Always make sure that arc thoroughly
−
passes through the piece to be cut and that it is not
tilted, when going forward, by an angle above 10 ÷ 15°
(see picture 6). It is thus avoided to wear nozzle (see
pict. 7) out and to burn the nozzle holder (see picture
8),
excessive thickness of piece (see graph of cutting
−
speed and thickness),
work clamp not properly in electric contact with piece,
−
worn nozzle and electrode,
−
too low cutting current.
−
N.B. : When the unit does not thoroughly pass through,
nozzle is clogged by scums.
2) Cutting arc switches off.
This may be due to:
worn nozzle, electrode or diffuser,
−
too high air pressure,
−
−
too low feed voltage.
3) Tilted cutting.
When cutting is tilted (see picture 9) switch the unit off,
loosen nozzle holder and turn nozzle by a quarter turn,
then lock and try again.
Repeat until cutting is straight (see picture 10).
4) Excessive wear of consumable parts.
This may be due to:
a) too
low
air
pressure
recommended one.
b) excessive burns on the end part of nozzle holder.
3.5 Practical recommendations
If the system air contains much humidity and oil it is
−
required to use a drying filter to avoid excessive
oxidation and wear of consumable parts, to avoid torch
damage or to reduce speed and quality of cutting.
Impurities of air favour oxidation of electrode and
−
nozzle and make it difficult to start pilot arc. If this
occurs, clean the end part of electrode and inside the
nozzle with fine abrasive paper.
−
Make sure that new electrode and nozzle to fit are
clean and degreased.
To avoid damages of torch always use genuine
−
spares.
3.6 Gouging ( Only for art. 494-496)
This operation permits to remove faulty welding, to
divide welded pieces, to prepare edges, etc. and is
almost exclusively used with manually controlled torch.
A nozzle Ø 3 mm should be used and spacer should be
fit into the nozzle holding bush. Spacer prevents molten
with
respect
to
the
metal from burning the insulating material covering the
nozzle holding bush, while gouging. The power value to
be used is from 80 to 150A. This operation is carried
out by keeping torch tilted and advancing towards the
molten material thus moving it away by means of the
out flowing compressed air. Torch is tilted depending
on the penetration to be obtained. As molten slag tend
to stick on spacer and nozzle it is recommended to
clean them often to prevent effects (double arc)
destroying nozzle in few seconds. Because of intense
radiation emission (both infrared and ultraviolet) the
operator as well as persons nearby are recommended
to use proper protection.
3.7 Torch maintenance
Always disconnect the unit before any repair of
torch.
1) Replace wear parts (picture 11).
The parts subject to wear are electrode 2, diffuser 3
and nozzle 4.
Either part may be only replaced after loosening nozzle
holder 5.
Electrode 2 should be replaced when a 1/16" (1,5 mm)
deep central crater develops (see picture 12).
ATTENTION!! Do not make sudden stresses when
unscrewing the electrode, but gradually force so as
to have the thread unlocked. Lubricate the thread of
the new electrode with silicone lubricant (on supply
with the unit). This new electrode has to be
screwed in its housing and locked without
tightening.
Nozzle 4 should be replaced when its central hole is
damaged or enlarged with respect to the new part (see
picture 13). Use of worn electrode quickly wears out the
nozzle. Excessive use of electrode causes overheating
and reduces the life of diffuser 3. Make sure that after
replacing it, nozzle 5 is tight enough.
ATTENTION!! Nozzle holder 5 should be only
screwed on head when electrode 2 diffuser 3 and
nozzle 4 are assembled.
2) Replace torch body 1 (see picture 11).
Remove the screw. Withdraw handle 9 from body 1 by
swaying it and making sure that button wires are not
torn when separating both parts. Withdraw the safety
contacts wires. Withdraw the contact . Unscrew fitting
after cutting the insulating hose . Assemble the new
body of torch making all above operations inversely.
11
Advertisement
