Safety in Welding, Cutting, and Allied Processes

ANSI Z49.1:1999
devices such as pins, blocks, or latches, shall be provided
where the platen or the head can move. The device, when
used, shall cause the energizing circuit to be broken, and
the device itself will prevent movement of the platen or
head under static load. More than one device may be required,
varying with machine size or accessibility, but each
device alone shall be capable of sustaining the full static
load involved.
12.6 Ventilation. Ventilation shall be provided in accordance
with Section 5.
12.7 Maintenance. Periodic inspections and necessary
repairs shall be made by authorized personnel. The operators
or maintenance personnel shall report any equipment
defects to supervisory personnel.
require the insertion of more than hands into the closure
area.
13. Electron Beam Welding
and Cutting Processes
(EBW and EBC)
13.1 General. These safe practice recommendations are
abstracted from the ANSI/AWS C7.1, Recommended Practices
for Electron Beam Welding.
13.2 Potential Hazards. The following potential hazards
associated with electron beam welding shall be guarded
against:
Electric Shock (13.2.1)
Gases and Fumes (13.2.2)
X-radiation (13.2.3)
Visible Radiation (13.2.4)
Vacuum (13.2.5)
13.2.1 Electric Shock. Appropriate precautionary signs
shall be affixed to the equipment.
All doors and access panels on electron beam welding
equipment shall be properly secured and interlocked to
prevent accidental or unauthorized access. All high-voltage
conductors shall be fully enclosed by grounded, conductive
barriers that are also interlocked. A grounding
probe shall be used before servicing the electron beam
gun and high-voltage power supplies.
13.2.2 Gases and Fumes. Positive exhaust ventilation
and filtering from the medium and non-vacuum EB processes
shall be provided. In high vacuum EB welding, extra
care shall be taken while cleaning the interior of the
vacuum chamber to ensure that vapors from the solvents
and cleaning solutions do not reach hazardous levels.
Before welding any unfamiliar materials or using any
unfamiliar cleaning materials, the Material Safety Data
E13.1 ANSI/AWS C7.1 should be consulted for a complete
treatise of the subject. Also, refer to Part I of this
standard for general safety considerations associated with
welding and cutting processes and equipment.
E13.2.1 The typical primary voltage to an electron beam
welding machine is 440 volts. Voltages used in the electron
beam welding processes are much higher than those
in most welding processes.
Whenever servicing (especially on energized systems)
is done on this equipment, a second person should be in
the area in case of accidental shock. The primary input
voltage is stepped up to several thousand volts for the electron
beam gun and also for the vacuum (ionization)
gauge(s). These voltages, and their associated currents,
are lethal.
E13.2.2 Ozone, nitrogen oxides, and metal fumes are
generated by electron beam welding. See 3.2.1.2 for more
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