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NEBOSH HSE PSM| Comprehensive Key
Questions With Answers
Superheated Steam-correct-answer-The superheated steam has a temperature
higher than its boilling point (for example 200 ⁰C) and it is more suited to transfer
long distances through pipework. It is an invisible gas and not readily detected by
naked eye.
Vacuum Steam-correct-answer-The vacuum steam is created by reducing the
operation pressure using a vacuum pump, so the steam effectively is below 100
⁰C.
Steam injected into flare stacks-correct-answer-Injecting steam into fluids
atomices the fluid and increases surface area. In the process industries, the steam
is often injected into flare stacks to improve combustion efficency and reduce
emissions of pollutants.
Legionella Pneumophilia Bacteria-correct-answer-This bacteria can survive when
water temperatures are in the range over 20 ⁰C and under 55 ⁰C. The ideal growth
temperature for the bacteria is 37 ⁰C (the human body temperature and hence
the risk). As well as causing pneumonia, the bacteria also can cause a fever
(Pontiac fever) that is generally less serious.
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Catalysed and Uncatalysed Reaction-correct-answer-A Catalyst is a medium put
into a reaction vessel that changes the pathway (mechanism)of a reaction
so the particles are forced into closer proximity. This increase the speed of a
reaction by lowering the
activation energy. Catalysts are not destroyed or changed during a reaction and
are generally reusable,
although they may suffer from poisoning by contamination with undesaired trace
substances in the reaction.
Measures to control and prevent a Run away chemical reaction-correct-answer-
Containment within the reactor.
Crash cooling.
Drowning and quenching of reactor contents.
Emergency venting/ dumping of reactants.
Types of static charges-correct-answer-Spark discharges.
Corona.
Brush.
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Propagating brush.
Conical pile (Maurer).
Streaming current charge.
Typical uses of Inert Gases (chemically inactive gases):-correct-answer-Inerting
equipment to prevent flammable atmospheres.
Preparing equipment for maintenance by purging out hydrocarbons.
Removing air/oxygen in equipment before start-up.
Blanketing tanks to prevent the ingress of air to avoid flammable atmospheres in
the headspace.
Pressure control blanketing-nitrogen introduced into the tank headspace to
maintain a set pressure.
Certain welding operations.
Decommissioning equipment to prevent the rusting process.
Instrument air backup.
Use of Inert gases as fire fighting agents-correct-answer-Typically CO2 is used for
this purpose in domestic and office areas and on some plant. For major industrial
use and process plants, a mixture of gases may be preferred. A typical mixture is
52% nitrogen, 40% argon, 8% carbon dioxide.
NEBOSH HSE PSM| Comprehensive Key
Questions With Answers
Superheated Steam-correct-answer-The superheated steam has a temperature
higher than its boilling point (for example 200 ⁰C) and it is more suited to transfer
long distances through pipework. It is an invisible gas and not readily detected by
naked eye.
Vacuum Steam-correct-answer-The vacuum steam is created by reducing the
operation pressure using a vacuum pump, so the steam effectively is below 100
⁰C.
Steam injected into flare stacks-correct-answer-Injecting steam into fluids
atomices the fluid and increases surface area. In the process industries, the steam
is often injected into flare stacks to improve combustion efficency and reduce
emissions of pollutants.
Legionella Pneumophilia Bacteria-correct-answer-This bacteria can survive when
water temperatures are in the range over 20 ⁰C and under 55 ⁰C. The ideal growth
temperature for the bacteria is 37 ⁰C (the human body temperature and hence
the risk). As well as causing pneumonia, the bacteria also can cause a fever
(Pontiac fever) that is generally less serious.
,2|Page
Catalysed and Uncatalysed Reaction-correct-answer-A Catalyst is a medium put
into a reaction vessel that changes the pathway (mechanism)of a reaction
so the particles are forced into closer proximity. This increase the speed of a
reaction by lowering the
activation energy. Catalysts are not destroyed or changed during a reaction and
are generally reusable,
although they may suffer from poisoning by contamination with undesaired trace
substances in the reaction.
Measures to control and prevent a Run away chemical reaction-correct-answer-
Containment within the reactor.
Crash cooling.
Drowning and quenching of reactor contents.
Emergency venting/ dumping of reactants.
Types of static charges-correct-answer-Spark discharges.
Corona.
Brush.
, 3|Page
Propagating brush.
Conical pile (Maurer).
Streaming current charge.
Typical uses of Inert Gases (chemically inactive gases):-correct-answer-Inerting
equipment to prevent flammable atmospheres.
Preparing equipment for maintenance by purging out hydrocarbons.
Removing air/oxygen in equipment before start-up.
Blanketing tanks to prevent the ingress of air to avoid flammable atmospheres in
the headspace.
Pressure control blanketing-nitrogen introduced into the tank headspace to
maintain a set pressure.
Certain welding operations.
Decommissioning equipment to prevent the rusting process.
Instrument air backup.
Use of Inert gases as fire fighting agents-correct-answer-Typically CO2 is used for
this purpose in domestic and office areas and on some plant. For major industrial
use and process plants, a mixture of gases may be preferred. A typical mixture is
52% nitrogen, 40% argon, 8% carbon dioxide.
