1.
Authorisation
§ Authorisation from academic-in-charge, is
required to undertake work in the metallography laboratory
§ Potential user should complete the risk control worksheet and
assessment
§ Potential user should be trained by a qualified or licensed user
2.
Hazards
associated with equipment/process:
§ Electrical hazards associated with the use 240 VAC electrical appliances.
§ Ultrasonic energy can cause damage to joint tissues if fingers or
any other part of a body is immersed in the cleaning fluid of an operating
ultrasonic cleaner.
§ Prolonged exposure to high frequency sound emitted from an operating
ultrasonic cleaner unit may lead to hearing impairment.
§ Organic solvent is flammable, harmful and may be reactive hazard if
mix with other chemicals.
3.
Preparation for
work:
§ Locate first-aid box, safety shower, eye wash, emergency telephone,
emergency exits and fire extinguisher.
§ Locate MSDS and risk assessment in the folder behind the lab door.
4.
Personal
protective equipment (PPE) to be used:
§ Safety glasses, closed-toe shoes, protective gloves, lab coat, mist
mask.
§ Loose and long hair should be tied back away from the face.
5.
The environment
where the task is to be undertaken:
§ The ultrasonic cleaner unit should be mounted on a level surface,
free from extreme temperatures, strong vibrations and corrosive environment to
protect the equipment from damage.
§ Working bench and floor should be dry and clean to avoid electric
shock, slip and contamination.
§
No naked flame, heat or
ignition source in the vicinity
§ No eating, drinking or smoking
6.
Step-by-step
working procedures
a)
Wear PPE as mentioned above.
b)
Visually inspect condition of
the ultrasonic cleaner unit and the electrical connection is satisfactory.
c)
If necessary, clean and fill
the tank with water to the appropriate level. Do not over fill with water that causes
water to spill over the top of the tank. Too low a water level will result in
poor cleaning efficiency and may cause transducers damage.
d)
Ensure that the external
surface and electrical connection are thoroughly dry before plugging the
cleaner to the mains supply.
e)
Suspend the stainless steel
mesh tray inside the water-filled tank. Items to be cleaned should not be placed
directly on the tank bottom; otherwise the transducers could be damaged because
of ultrasonic energy reflecting directly back to the transducers
f)
Fill a small beaker with the
cleaning solution to the level sufficient to cover the item to be cleaned.
g)
Gently lower the beaker onto
the mesh tray suspended inside the water-filled tank. Care should be taken not
to allow water to overflow the top of the tank. The beaker should be stable
when seated on the mesh tray. Otherwise add more cleaning solution for more
weight.
h)
Switch on the unit to degas
both the water and the cleaning solution. Cover the lid to reduce noise and
aerosols escaping. Degassing will provide optimal cleaning.
i)
After 5-10 mins of degassing,
switch off the unit and gently put the item to be cleaned (using a pair of
forceps or tongs) in the beaker of cleaning solution. Switch on the unit and
cover the lid.
j)
Monitor the cleaning process
regularly; if necessary, use the timer switch. Switch off the unit to inspect
the item.
7.
Clean-up
procedures
§
If the water in tank is
contaminated, unplug the unit from the mains before draining the contaminated
water.
§
Thoroughly rinse the tank with
fresh water. If necessary, clean inside of tank with sponge and mild detergent.
§
Fill the tank with clean water.
§
Dry all external surfaces of
the unit with particular attention on the electrical connection and socket.
8.
Waste disposal
procedures
§
Dispose of any waste organic solvent in the
designated receptacle for eventual disposal through Chemsal.
§
Dispose of other cleaning solutions as per
respective MSDS guidelines.
9.
Emergency
procedures
§
In case of emergency alarm or power
outage, leave the lab in an orderly manner.
§
Use the emergency red phone or
dial ‘333’ for any emergency.
§
For minor injury requiring
first aid treatment, use the first-aid cabinet or contact the nearest
first-aider.
§
In case of minor spills, wear
appropriate PPE and wipe spills with paper towels.
§
Report any major spills; a
general chemical spill treatment kit (in Room 179) may be used. Refer to MSDS
for further procedures.
§
If contact with acetone or
ethanol, rinse skin or eyes with fresh running water.
10.
After-hours
access procedures
§
After-hours access is
restricted; contact person-in-charged for after-hours authorization.
§
Register your details in the
after-hours log book if the metallography lab is to be used after normal
working hours.
§
Only trained and licensed user
of the equipment is allowed to enter the log book.
11.
Associated Documents
§
Risk assessment for ultrasonic cleaning
§
MSDS for ethanol
The cleaning solution should be suitable for the wartsila spares parts that to be cleaned.Ultrasonic cleaners use special cleaning solutions to clean grime even from the inside of cracks in the tiniest parts.The solution and the parts to be cleaned are placed inside the ultrasonic cleaner.Ultrasonic parts cleaners are like pressure pumps that use high-pressure water or chemicals to clean even the toughest and oldest grime from hard to reach places.
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