PN 376 - Cylinder procedure Flashcards
PN 376 - Cylinder procedure
Describe cylinder colours according to their contents
- Acetylene - maroon
- O2 - white
- Argon - (dark) green
- Nitrogen - black
- CO2 - grey
- Helium - brown
PN 376 - Cylinder procedure
Colour classification by hazard property?
- Bright green - INERT
- Red - FLAMMABLE
- Pale blue - OXIDISING
- Yellow - TOXIC
- Yellow/Red - TOXIC (AND/OR CORROSIVE AND FLAMMABLE)
- Yellow/Light Blue - TOXIC (AND/OR CORROSIVE AND OXIDISING)
PN 376 - Cylinder procedure
What is the practical behavioural difference between a composite cylinder and one that looks composite but has an alluminium layer?
The alluminium layer will not allow the gas to escape.
PN 376 - Cylinder procedure
1.2 - A cylinder can be defined as…
A cylinder can be defined as any vessel containing a gas or liquid under pressure
PN 376 - Cylinder procedure
1.3. - Gases are stored in one of three ways:
- a liquefied form (e.g. LPG),
- as a compressed gas (e.g. oxygen), or, in
- the case of acetylene dissolved in a solvent and stored in special cylinders containing a porous mass within the steel shell.
PN 376 - Cylinder procedure
1.4 - Cylinders are constructed in one of 4 ways:
- Welded cylinders: two steel halves welded together around the centre.
- Drawn steel: a single steel skin containing no weld.
- Aluminium cylinders: lighter in weight than steel cylinders and used to contain specialist gases.
- Composite cylinders: a woven “fabric” jacket impregnated with resin and protected by a hardened plastic outer cage. This type of cylinder is mainly used for LPG but can be found with various contents. Occasionally these cylinders can have an aluminium inner lining.
PN 376 - Cylinder procedure
1.7 - ICs will be supported in their RA decision making process by the
HMEPO attending the incident. They, in turn, may be supported by…?
…the British Compressed Gas Association (BCGA) competent person
and/or the Scientific Adviser (SA) - where appropriate.
(BCGA CP)
2 Hazards and operational considerations
2.1 - All cylinders, regardless of their contents, are at greatest a risk of failure when subjected to direct flame impingement.
As a cylinder is heated the steel or aluminium shell loses its tensile strength which is what temperature:
- [what] for steel
- [what] for aluminium
- 300oC for steel
- 200 – 250oC for aluminium.
All cylinders ultimately fail because the shell reaches a point where its tensile strength weakens and can no longer contain the increasing internal
pressure. In the case of composite cylinders the resin will begin to break down and becomes porous.
2 Hazards and operational considerations
2.2 - Where a composite cylinder is involved in direct flame impingement the cylinder may become porous
How would this be evident?
By a substantial increase in the size of the fire as it will be fed by the gas from inside the cylinder.
2 Hazards and operational considerations
2.3 - In a situation where a composite cylinder is involved in a direct flame impingement and the cylinder has not yet become porous, the fire can be extinguished and the cylinder cooled.
However, caution should be taken when moving any composite cylinder as the resin may have become weakened to an extent where it may begin to leak when handled. In these situations what is the best course of action?
It is best to leave the cylinder in situ and consult the HMEPO.
PN 376 - Cylinder procedure
2.4 - Some composite cylinders cannot be identified as solely composite must be treated as…?
As having an aluminium inner lining. In these situations the cylinder should be treated as a steel cylinder and cooling water should be applied.
Treating them as steel cylinders involves cooling them to ambient temperature.
However, as aluminium will fail at lower temperatures to steel there is a possibility that the cylinder may have already failed and the contents are burning off.
The HMEPO can advise if the contents should be allowed to burn off or if gas dispersal techniques (such as the application of a fine spray) would be appropriate.
2 Hazards and operational considerations
2.7 - Why is the initial HZ for steel cylinders 200m?
+
What might be considered to allow this to be reduced?
Any steel cylinder that fails has the potential to project fragments up to 200m.
Therefore, if it is at risk of failure (i.e. it has been substantially heated, or is being subjected to direct flame impingement) an initial Hazard Zone (HZ) of 200m must be implemented around any cylinder.
Acetylene cylinders are designed to fail in ductile mode and split along their entire length. However, if a partial split occurs the cylinder itself can be propelled up to 200m.
+
Full consideration should be given to the availability of substantial cover and how this may allow the initial HZ to be reduced.
2 Hazards and operational considerations
2.8 - Where advice or assistance in addition to that being given by the HMEPO is required who might HMEPO consult, on behalf of the IC?
Where advice or assistance in addition to that being given by the HMEPO is required then the HMEPO may consult, on behalf of the IC, with the BCGA CP via Brigade Control.
3 Preplanning
3.1 - Station personnel should gather information on the risks on their own stations ground to locate premises which may contain cylinders and what types are likely to be present. This information may be included in:
(3)
- 7 (2)(d) visits.
- Local knowledge.
- Operational risk database on the mobile data terminals (MDT).
3 Preplanning
3.2 - Actions en route
Once an IC becomes aware that cylinders may be involved in a fire, either by additional information supplied by Brigade Control or by the nature of the premises, on arrival tactics should be carefully considered. Consideration should be given to:
(5)
- A safe route of approach and the subsequent positioning of appliances.
- The possibility of acetylene cylinders being involved.
- The use of the initial hazard zone overlay.
- The surrounding risks that may become involved if a HZ is implemented – railway lines, major roads or public buildings etc.
- Early notification to Brigade Control of an appropriate RVP.
- Any additional information received from Brigade Control or locally.
3 Preplanning
3.3 - Actions on arrival
Appliances should be parked in a manner which affords them suitable protection from a cylinder should it fail. ICs should direct appliance drivers to make use of surrounding buildings and structures to protect vehicles and crews. It is important that early consideration is given to what?
An appropriate RVP and approach route
which, once established, should be communicated to Brigade Control for transmission to all oncoming vehicles which form the attendance at the incident.
This prompt action by the IC helps to manage the HZ if required and reduces the potential for oncoming vehicles travelling through any intended HZ.
3 Preplanning
3.3 - Actions on arrival
Appliances should be parked in a manner which affords them suitable protection from a cylinder should it fail. ICs should direct appliance drivers to make use of surrounding buildings and structures to protect vehicles and crews. It is important that early consideration is given to what?
An appropriate RVP and approach route
which, once established, should be communicated to Brigade Control for transmission to all oncoming vehicles which form the attendance at the incident.
This prompt action by the IC helps to manage the HZ if required and reduces the potential for oncoming vehicles travelling through any intended HZ.
4 Operational procedure
4.3 - What should initial crews try to establish that will determine the appropriate course of action?
+
What should crews pay particular attention to establishing?
Initial crews discovering a cylinder should make every effort, without exposing themselves to un-necessary risk, to identify:
- the type,
- size,
- contents,
- location and
- number
of any cylinders involved
+
In particular, crews should attempt to identify if the cylinder is acetylene or not
4 Operational procedure
4.5 - Once cylinders have been confirmed at an incident the IC should send an informative message. Give an example…
“From…………….
At…………….
1 x industrial unit 20m x 20m, 15% alight, 1 x 85Kg acetylene cylinder confirmed involved, cylinder procedure being implemented”.
4 Operational procedure
4.6 - Once cylinders have been confirmed the IC must carry out a risk assessment. What will determine the ICs subsequent actions?
- content
- number
- location
- condition of the cylinder(s)
4 Operational procedure
4.7, 4.8 - When can it be considered that the cylinder is in no immediate danger of failing and therefore is NOT necessary to implement a 200m hazard zone?
If following a dynamic risk assessment the IC can determine that all of the following can be established:
- The fire has been extinguished.
- The cylinder(s) are definitely not acetylene.
- All the cylinders present have been located.
- The cylinders involved are receiving direct cooling.
Following a risk assessment, only a cordon around the incident sufficient to maintain a safe system of work (SSOW) is required.
If the IC is unable to determine all of the four factors then the appropriate (acetylene/non-acetylene) cylinder procedure MUST be implemented.
4 Operational procedure
4.10 - Any cylinders that have not been involved in the initial fire, but are at risk of becoming involved, should be removed to a place of safety. Firefighters need to remain aware of their surrounding and ensure cylinders are moved safely.
Visual indicators that a cylinder has not been involved could include:
(3)
- Paper labels and plastic rings are intact.
- The paintwork has not been blackened or blistered.
- The supply hose pipes are undamaged.
4 Operational procedure
41.4 - Secondary actions non–acetylene
Can crews work inside a hazard zone?
+
What level of PPE is required when working within 25m of a heated cylinder.
A HZ is not an exclusion zone; crews may work in this area following a risk assessment by the IC.
When working within the HZ crews must work behind substantial cover where available and be wearing full structural fire fighting PPE (fire kit, fire hood, gloves).
Where crews are working within 25m of a heated cylinder BA should also be worn.
4 Operational procedure
4.15 - Secondary actions non–acetylene
Once cylinder procedure has been implemented, the IC should then send an informative detailing…?
(5)
- Actions taken.
- The number of evacuees.
- The HZ size and road closures.
- The RVP and approach route.
- The tactical mode.


