HSO 2024 to HSO 2035 Installation, Operation and Maintenance Manual
Issue 1.2 : 03/10
Publication 2-119
Page 3 of 94
Safety
In common with most other forms of mechanical and electrical
equipment, there are a number of potential hazards associated with
operating and servicing refrigeration plant.
In writing this instruction manual every emphasis has been given to safe
methods of working. These safety instructions are intended to draw
attention to the potential hazards that could be encountered during
installing, operating and maintaining the plant. At the same time, it
should be emphasised that these notes are not exhaustive, and are
principally intended to draw attention to the most important points; where
necessary, reference is made to other parts of the manual.
Please note that the installer is responsible for the correct installation of
equipment, and on completion, the owner and/or user are responsible for
safe operation and maintenance.
Personnel Permitted to Install, Commission and Maintain the Plant
It is essential that only authorised and competent personnel are allowed
to install, commission and maintain the plant. A permit to work system
should be introduced before commissioning begins, and should be
rigorously enforced thereafter.
Any person rendering assistance or under training must be supervised by
the authorised competent person who has responsibility for safety.
Personnel must be familiar with the plant’s construction, operation and
the hazards involved.
All
personnel should make a thorough study of
these instructions before undertaking installation, commissioning,
maintenance or repair procedures.
WARNING
A minimum of two personnel should always be present
when working on ammonia refrigeration plant.
Mechanical
Refrigeration compressors manufactured and/or supplied by J & E Hall
International must be operated within their design parameters, and
should never be used as vacuum pumps or for compressing air.
Personnel must not start the plant until they have taken steps to verify the
following:
•
Guards on couplings, belt drives and fans are in place, and
other personnel are not in positions that might be hazardous
when the plant is in operation.
•
The compressor discharge stop valve is fully open.
Parts of the plant, specifically the compressor, drive motor and discharge
line, are liable to be at temperatures high enough to cause a burn. A
‘cold’ burn can result from accidentally touching any part of the plant
containing oil at low temperature, or subcooled liquid refrigerant.
Personnel who stop the plant must be aware of the potential hazard if
pipeline stop valves are closed in such a manner as to trap cold liquid
refrigerant between valves. If this should accidentally occur, rising
ambient temperature will cause the liquid to expand and eventually
fracture the pipe or valves, etc.
Stop valves should be opened slowly to begin with and by a small
amount, say half a turn, before the valve is fully opened. This procedure
allows system temperatures and pressures to equalise gradually, so
reducing the risk of physical and/or thermal shock which might cause
damage.
