STG global TANVAC HDV3000, Руководство оператора

Страница: 24 / 329

21
Under normal conditions, the absence of oxygen minimises the risk of ignition in a
vacuum truck. However, operating rotary lobe blowers and vacuum pumps at high
speeds creates high air movement and high vacuum levels, resulting in high
discharge air temperatures and high discharge vapor concentrations that can present
potentially ignitable conditions.
10. ATMOSPHERIC TESTING
The areas where vacuum trucks will operate must be free of hydrocarbon vapors in
the flammable range.
*The areas where the vacuum truck operator and others work without respirators
must also be at or below air contaminants PELs/STELs. If there is any question
whether the area is vapor or toxic gas free, atmospheric testing shall be performed by
a qualified person using properly calibrated and adjusted detectors.
Testing shall be conducted prior to starting any operations, and if necessary
during operations, including, but not limited to the following:
• When operations in the area are subject to change, such as automatic pump
start-up or product receipt into, or transfer out of a tank located near the
transfer operations.
• When off-loading
• When atmospheric conditions change, such as wind direction
•
When an emergency, such as product release, occurs within the facility that
may affect atmospheric conditions in the transfer area
To prevent exposure to toxic gases during transfer operations:
• Never transfer fluids from one truck to another unless it has been established
that no chemical reaction will occur
• Position trucks to minimise exposure to any discharged gases and fumes.
• Ensure that discharge lines are long enough and large enough for safe
operation.
• Position vent lines away from workers and workstations, including control
panels, valve handles, gauges, shut-offs, and hose attachment points – if