Helvi 1357 Manual De Uso Y Manutención página 19

IMPORTANT: make sure that the polari-
ty is correctly set. For GAS welding the
ground cable must be connected to the
negative terminal (-), while the torch must
be connected to the positive terminal (+)
(FIG.5) *.
• Connect the ground clamp to the workpiece
and make sure that the contact is good;
• Make sure that the wire-feeding roll is cor-
rectly positioned (groove matching the wire
diameter). Use the groove marked by 0.9mm
for all the wires with diameter 0.8mm and the
groove marked by 0.7mm for all the wires
of diameter 0.6mm. In order to change the
groove loosen the screw that locks the roll,
turn the roll and fix it again with the screw;
• Open the gas using the pressure regulator
and adjust the flow rate. (NOTE: The gas flow
may need adjustments in order to obtain a
better welding, this depends on the type and
thickness of the metal used, anyway the gas
flow should be maintained as low as possi-
ble).
* Operation valid only for Gas - No gas models
CONNECTION OF THE GAS
CYLINDER AND REGULATOR
• When using disposable gas cylinders (S), re-
move the protective cap from the top of the
gas cylinder and screw the gas regulator (T)
rotating it clockwise and fixing it tightly (do
not force).
• Connect the gas hose (fig. 2,Q) to the regu-
lator (insert it completely). Note: To discon-
nect the gas hose from the regulator hold
Fig.5
back the ring (U) and pull. The pressure re-
gulator used with disposable gas cylinders
operates through a needle controlled by a
knob. The knob, positioned on a graduated
plate marked from 0 to 6, regulates the gas
gauge. When the knob is on 0 there is no
gas flow; before starting to weld, position
the knob on 3 or 4, the gas flow in this case
is 2/3 lt/min. In order to better use the gas
cylinder, always keep the minimum gas flow
(2/3 lt/min.) that can grant a good welding
without porosity. The gas regulator is equip-
ped with a security valve that intervenes au-
tomatically when the gas flow changes.
• For security and cost reasons, make sure
that the regulator is well closed (turn counter
clockwise to the end) when not welding and/
or before changing the gas cylinder.
• When using rechargeable gas cylinders,
connect the plastic gas hose (Q) to an adap-
ter for big gas cylinders (V). Connect the end
of the adapter to a 6mm flexible gas hose
and to the exit of the pressure regulator/
flowmeter mounted on the gas cylinder. The
regulator/flow meter serves to control the
gas flow, which should be ca. 2/3 litres per
minute.
MATERIAL
TO WELD CYLINDER
Argon+Co2
Soft steel c y l i n d e r o r
Co2 cylinder
Stainless steel Argon cylinder
Aluminium Argon cylinder
Fig.6
GAS
WIRE
Coppered steel
wire spool, for
no gas welding
flux-cored wire
spool
Stainless steel
wire spool
Aluminium
wire spool
GB
19