and current used. Follow the guidelines in the
here below table.
Coated
DIN
Electrodes
9
10
40-79A
11
80-174A
12
175-299A 225-274A 100-174A
13
300-499A 275-349A 175-249A
• Glass screens must always be kept clean,
and immediately replaced if they are broken
or cracked (Fig.3). It is good practice to in-
stall a pane of transparent glass on top of the
adiactinic glass, between it and the welding
area to protect it from molten and hard parts
and arc rays. This pane can be frequently re-
placed when incandescent spatters and de-
posits greatly reduce visibility.
2.3 WORk AREA
• Welding should be done in a ventilated and
closed area that does not open onto other
working areas, in order to protect all workers
against radiation and fumes. If such an area
cannot be provided, other operators and as-
sistants close to the welding area shall be
protected by interposition of opaque transpa-
rent curtains and screens, flame retardant
and complying with the local legislation (color
of the protective curtains depends on the wel-
ding process and on the welding currents), by
use of anti-UV glasses and if necessary of a
mask with suitable protective filter. (Fig. 4).
• Before welding remove from the welding
area all chlorinated solvents commonly used
to clean or degrease the working metal. Cer-
tain chlorinated solvents decompose when
exposed, even at a certain distance, to the
4
Carbon
Electrodes
TIG
Arc/Air
5-19A
125-174A
20-39A
175-224A
40-99A
Fig.3
Fig.4
electric arc radiation to form phosgene gas.
The parts degreased with a solvent must be
dried before welding.
CAUTION: when working in a closed
area, never use chlorinated solvents if
electric arc may occur.
• When grinding, brushing, hammering, etc..
of welded parts, always wear protective gog-
gles with transparent lenses to prevent splin-
ters or other foreign particles from harming
the eyes (Fig. 5).
• The gases and fumes unhealthy or hazar-
dous to the health of workers must be aspi-
rated (as they are produced) as closely and
effectively as possible to the source of their
emission to prevent any concentration of pol-
lutants that may exceed the limits defined by
the local legislation. (Fig.6)
• Welding process must be performed on
metal coatings thoroughly cleaned from la-
yers of rust or paint, to avoid production of
harmful fumes.
• Any symptom of stain or soreness to the
eyes, the nose or the throat may be cause by
inadequate ventilation; work must be stopped
immediately and all necessary steps must be
Fig.5
Fig.6