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| Technical Information Bulletin |
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U.S. Department of Labor
Occupational Safety and Health Administration |
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Potential Ejection Hazard Associated with High Speed
Separators in Rendering Operations
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| TIB 01-06-20 |
This TIB is not a standard or regulation
and it creates no new legal obligations. It is
advisory in nature, informational in content,
and is intended to assist employers in providing
a safe and healthful workplace.
For a more detailed description of the nature
and effect of Technical Information Bulletins,
see the Important Information box at the end of
this bulletin. |
Purpose
The purpose of this Technical Information
Bulletin is to provide employers and employees
who operate, service, and maintain high speed
separators with information about the potential for
ejection of machine parts during operation, if not
properly assembled, operated, inspected and maintained.
Background
The Wichita Area Office brought to the attention
of the Directorate of Technical Support a fatality
investigation conducted in the rendering department
of a beef processing facility. In the accident, the
rendering operator sustained fatal injuries and another
employee suffered non-fatal injuries when they were
struck by flying parts ejected from a high speed
separator.
Incident Description
The high speed separator (see Figure 1), located
in the rendering department of a beef processing
plant, was used to separate water, solids, and tallow.
Purified tallow was the desired end product. The
separator had not been running properly on the day
before the accident. The operators and maintenance
employees disassembled and reassembled the
machine two or three times in an effort to get the
machine to properly “run product.” (Disassembly of
the machine requires removal of the frame hood,
coupling ring, and bowl assembly. When the
machine is reassembled, the bowl assembly is held
together by the coupling ring, which threads into the
separator bowl body. The coupling ring and all the
bowl assembly parts have alignment marks to ensure
that the parts are correctly placed. According to the
manufacturer’s instructions, in the event of excessive
thread wear, which is indicated when the coupling
ring is tightened and the alignment mark on the
coupling ring exceeds the alignment mark on the bowl
bottom by 25 degrees or more, the manufacturer
should be contacted immediately because this
situation indicates excessive wear of the bowl threads,
a condition that is dangerous to users and may damage
the equipment. The manufacturer’s instructions also
warn that the user should check for thread wear
periodically, since thread wear is not always related to
a rough running bowl.)
On the day of the accident, the operator had just
reassembled the machine. After various parts were
replaced (it is not known whether the alignment mark
on the coupling ring was properly aligned with the
mark on the bowl bottom), the separator was started
and was running for approximately 5-6 minutes when
the frame hood and the parts from the bowl assembly
were ejected from the machine, striking the operator
and a maintenance employee. The operator, who
apparently was adjusting the feed rate, was struck in
the head and upper chest and was fatally injured. It is
believed that the separator was at or near its full
operational speed of 4,500 rpm at the time of the
accident. According to the maintenance employee,
just prior to the ejection the separator appeared to be
running smoothly, with no visual or tactile indication
of vibration; the maintenance employee did not detect
any vibration when he placed his hand on the machine.
Recommendations
High speed separators, if not properly
assembled, operated, and maintained, may forcefully
eject separator parts, exposing employees in the area
to hazards associated with flying objects.
OSHA makes the following recommendations
to employers and/or workplace users of high speed
separators:
- Establish an overall mechanical integrity program,
including a preventive maintenance program to
maintain the on-going integrity of the process equipment.
Perform routine, thorough inspections of the
machine and bowl assembly. These inspections are
to be performed by qualified individuals who have
received appropriate training and who are familiar
with manufacturer instructions and recommendations.
To ensure safe operation of the high speed
separator, all machine parts must be carefully
inspected on a routine basis for excessive wear,
with particular attention given to coupling ring wear,
to confirm that all parts are within tolerances
outlined by the manufacturer and consistent with
good engineering practice. Inspections should be
documented and routinely reviewed by management
to ensure they are being properly and
regularly performed and that timely corrective
actions are taken. Immediately correct any
deficiencies outside of the manufacturer’s acceptable
limits for the equipment. Contact the manufacturer
or other qualified individuals who have
received appropriate training and who are familiar
with manufacturer instructions and recommendations
with any questions concerning acceptable
tolerances or to obtain assistance in determining
whether separator parts are excessively worn.
Non-destructive testing may be a useful method to
detect mechanical integrity deficiencies in equipment.
The type and frequency of inspections and
tests must be consistent with the manufacturer’s
instruction, good engineering practice, and operational
needs, as determined by prior operating
experience.
Figure 1 - High Speed Separator |
- Ensure that any vibration detection/monitoring
system in use on the separator is functioning
properly when the separator is in operation. Maintain,
calibrate, and test each piece of equipment in
accordance with established mechanical integrity
procedures, manufacturer’s instructions and
recommendations and good engineering practices.
- Ensure that employee training provides a complete
explanation of the operation and maintenance of
the separator, including: assembly, disassembly,
inspection of the condition of the separator and its
component parts (including the bowl assembly
parts), routine maintenance needed, and potential
safety hazards associated with incorrect assembly,
lack of proper maintenance, inadequate inspection
of the condition of the separator parts or improper
use of the separator, in accordance with the
manufacturer’s instructions or recommendations.
Provide training for non-English speaking
workers who are unable to read the operator’s
manual in English.
- Develop and implement written operating procedures
to provide clear instructions for safely
conducting separator activities. These procedures
should address, at a minimum, the following:
- steps for each operating phase (startup;
normal operations; emergency and normal
shutdowns);
- safe operating limits, including the
consequences of deviations and steps required to
correct or avoid deviation; and
- description of separator components
(e.g., pressure regulators; relief valves; vibration
detection/monitoring equipment; water control
valves), their functions, and safe work practices
(e.g., mechanical integrity procedures, including the
separator assembly and disassembly safety instructions;
prohibition of work in a trajectory zone).
- Ensure that the man-machine (ergonomic)
interface is considered and incorporated into the
separator operations to ensure that employees
remain safely outside the trajectory/projectile zone
danger areas while performing tasks. For example,
ensure that the location of the product feed control
valve relative to the separator equipment eliminates
the need for employees to be in the dangerous
trajectory/projectile zone during operation of the
separator.
Important Information on the Nature and Effect of Technical Information Bulletins
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OSHA’s Directorate of Science, Technology and Medicine (DSTM) issues Technical Information Bulletins
(TIBs) to provide information about occupational
hazards and /or to provide information about
noteworthy, innovative, or specialized procedures,
practices and research that relate to occupational
safety and health. DSTM selects topics for TIBs from
recognized scientific, industrial hygiene, labor,
industry, engineering, and/or medical sources.
The Occupational Safety and Health Act
requires employers to comply with hazard-specific
safety and health standards. In addition, employers
must provide their employees with a workplace free
from recognized hazards likely to cause death or
serious physical harm under Section 5(a)(1), the
General Duty Clause of the Act. Employers can be
cited for violating the General Duty Clause if there
is a recognized hazard and they do not take appropriate
steps to prevent or abate the hazard. However,
the failure to implement TIB recommendations
is not, in itself, a violation of the General Duty
Clause. Citations can only be based on violation of
standards, regulations, and the General Duty
Clause.
Further information about this bulletin may be
obtained by contacting OSHA’s Directorate of Science, Technology and Medicine at 202-693-230 |
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