Fuel tank entry Flashcards
What is a confined space defined as
An enclosed or partially enclosed space which
1) is at atmospheric pressure during occupancy
2) is not intended or designed primarily as a place of work
3) may have restricted means for entry and exit
4) is liable at any time to
- have an atmosphere which contains potentially harmful levels of contaminant
- have an oxygen deficiency or excess
- cause englufment
entry is defined as
when a persons head or upper body is within the boundary of the confined space
definition of a competent person
a person who through a combination of training, education and experience has squired the knowledge and skills to correctly perform a specified task
Define the LEL
level below which the gas air mixture is too lean to burn
What is the hierarchy of legislation
- Health and safety at work act 2015
- AS/NZS 2865
- NZAP 6000-1, CH 11
when does a duty holder commit the reckless conduct in respect of duty
1) they have a health and safety duty under sections 36-46 of HSWA
2) they engage in behaviour that causes someone to be put at risk of being seriously injured, made seriously ill or killed
3) the person at rish is a person to whom the duty holder owes the health and safety duty
4) the duty holder is reckless about the risk of injury, illness or death
5) they do not have a reasonable excuse
Atmospheric hazards include
- oxygen levels
- flammable/ explosive contaminants
- toxic contaminants
- temperature extremes
other hazards include
- Engulfment/ flooding
- Electric shock
- Fire and explosion
- Noise
- Radiation
- Slips, trips and falls
- manual handling
- Entrapment
- artificial lighting
Atmospheric assessment must include a test for
- unsafe level of oxygen
- flammable or explosive contaminants
- toxic contaminants
What are the 2 types of atmospheric assessment
-atmospheric monitoring:
continuous measurement over an uninterrupted period of time
-Atmospheric testing:
short term testing, recorded at set intervals
what is the safe oxygen range
- 5-23.5
20. 9 is normal
what happens to the body if it is oxygen deprived
impaired judgement and breathing- 16%
unconscious- 12%
death-6%
when can safe entry for avtur occure
5% of LEL, or 350 PPM
The presence of toxic atmospheres may be caused by
- generation by natural process of decomposition
- accidental spillage or leakage
- exhaust gases
- substance contained in the space
in the event of chemical over exposure…
- refer to the relevant MSDS for first aid procedures
- report to medical ASAP with MSDS
RNZAF conditions for safe entry to AC fuel tanks
- combustible vapor concentration within the fuel tanks must be below 350PPM/5%LEL and be continuously monitored
- air supplied respirator must be worn above 29PPM
- oxygen level must be below 23.5%
- air supplied respirator must be worn below 19.5%
- temp must be between 0-40*C
- if contaminants other than AVTUR are present an air supplied respirator must be worn
temperature limits for CSE
temp must be between 0-40*C
vapour concentration x_ for a __*C rise in temp
x2 for a 10*
x4 for a 20*
x8 for a 30*
what is a risk assessment
determination of the level of risk related to a specific situation and a recognised hazard. requires the calculation of the consequence and the liklihood
Hierarchy of control measures
1) elimination
2) substitution
3) isolation
4) engineering controls
5) administrative controls
6) use of ppe
when must an entry permit completed and when does it renew
part A; completed at the commencement of each AC servicing
Part B: issued no more than 1 hr prior to fuel tank entry. renewed when:
- 10 hours have elapsed from the time of issue
- significant change in the risk inside the fuel tank
- significant break in work continuity
where is the entry permit displayed
as close to the entry point as possible
how long must you wait for venting before entering
at least 30min
who is in a fuel tank entry team
NCO IC CSE
fuel tank entrant
stand by person
what are the best methods of rescue
1) self rescue
2) removal by someone who is outside the space (harnesses, lifelines)
3) where entry is necessary to extricate a victim
when raising the alarm, what should be adhered to
- gain attention
- give your name
- give your location
- state problem
- state condition of victim
- state what help is required
- check message details
- repeat if necassary
what are some hazards associated with establishing the work area
no hot work to be carried out while fuel tanks open
all electrical equipment meets the requirements.
what must you do with tools and consumables being taken into the fuel tank
must be recorded on rnzaflog 76
ventilation of confined spaces- points to note with forced ventilation
1) blower cart bonded to AC
2) venting hoses placed at opening of tank and metal ends touching structure
3) blower set to MAX and COLD
what is a precaution to be noted when using forced mechanical ventilation
pressure differential must be considered/monitored to prevent damage to structure
when ventilating AC with fuel tanks with a capacity over 8000lts, what must happen
venting airflow must be greater than 9000lt/min.
1x rhine blower
2x muft cart
what do the multi rae alarms sound like and when do they go off
soft slow beep- oxygen falls below 19.5%
rapid loud- oxygen excess over 23.5%
where do you place the multi rae when in the fuel tank
as close as practicable to your breathing zone
what will happen if the compressor air supply fails
1) a whistle will sound by the air cleaner unit
2) safety man will tell you to exit
3) safety man turns on emergency bottle
4) a whistle will sound when the bottle air supply is almost empty
what check must you do on an air bottle prior to use
ensure its 80% full.
above 2400 psi
immediately return to fresh air if
- you smell or taste contaminants, or your eyes, nose, throat become irritated
- it becomes difficult to breathe
- air you are breathing becomes warm
- you become dizzy
- warning alarm sounds
due to the physiological factors associated with wearing full body ppe, what must you be aware of
1) be in ppe no longer than 3.5 hours
2) be inside a confined space for longer than 3 hrs
3) make a second tank entry on the same day when you have already spent 2hrs inside wearing full ppe
Time Weighted Average is -
average airborne concentration when calculated over 8hr/ 5 days
Short term exposure limit is -
15min/ 4x per day. 60min break
Peak is-
maximum airborne concentration over the shortest analytically practicable period which doesnt exceed 15mins
