Offshore Passive Fire Protection (PFP) - 8 Flashcards
Fire protection should not to be confused with fire prevention. Fire prevention equipment is ,,,,,
Extinguishers and
Hoses to sprinklers
PFP is the materials used ,,,,,,
to minimize the effects of a fire when the prevention has been unsuccessful and the fire is established
Fireproofing needs to be applied to areas, such as;
- accommodation,
- production and compressors modules;
- escape routes and the
- primary structure of the platform,
- where there is risk to personnel and production plant
Hydrocarbon fire temperatures can reach 1250°C in a very short time; this is referred to as;
thermal shock
The thickness of the PFP applied and in some instances, type, depends on four main factors:
- Type of Fire
- Core Temp. of steel
- Length of time at which PFP has to maintain temp.
- The Hp/A factor
The Hp/A factor (section factor principle) is;
the ratio of the exposed heated perimeter of the steel member, divided by its cross-sectional area
The smaller the cross-section of a member,,,,,,, ;
the less steel there is to absorb the heat
the member will conduct heat more easily
Therefore, the smaller the cross-sectional area,,,,, ;
the thicker the PFP will need to be
PFP calculations already listed in table form in book called commonly
yellow book or Constrada.
PFP calculation for off shore platforms section, plate, girder need to be done, but not by,,,, ;
Inspector
,,,,, type of codes are used for different fire rating given for bulkhead, underdecks and similar sections and are exposed in code form
- A-60 class division
- B-15 class division
- H-120 class division
The most frequently encountered fire ratings are ,,,,,,, ;
- the A and H ratings
This type of fire can take quite a long time to build up to high temperatures. ;
- cellulosic fires, typically (wood, paper and fabric)
Jet fires can produce temperatures up to,,,,,, ;
- 1400oC and are extremely dangerous
The two most widely used materials offshore being ,,,,, ;
- epoxy intumescent and cementitious
PFP coatings are often referred to as ,,,,,,, ;
- fire resistant or flame-retardant coatings
PFP coatings have no ,,,,,,,,properties ;
- anti-corrosion
PFP coatings are applied over an ,,,,,,,,,,coating;
- anti-corrosion
Intumesce means to ,,,,, ;
- swell
Intumescent epoxies are ,,,,,, ;
two pack 100% volumetric solids (VS) high viscosity coatings
To bring the materials to suitable spraying viscosity, ,,,,,,is required and when mixed, this considerably shortens the ,,,,, ;
- Heat
- pot life
PFP material is applied through ,,,,,, ;
- Plural spray (spray gun)
Because of the viscosity of the material a fairly large tip is necessary, around ,,,,,,,, ;
- 35 thousand.
The material can be applied in coats up to ,,,,,,,,, ;
- 7mm
It is normal practice to ,,,,,,,,areas of overlap to avoid over thickness and a reinforcing mesh of ,,,,,,,, material can be rolled in at the same time ;
- trowel out
- synthetic
Intumescent epoxies work by ,,,,,,,,when submitted to flame action at ,,,,,,,, oC, releasing acid, which reacts with spumific materials, releasing non-combustible gases such as ,,,,,,,,, vapour ;
- softening the resins
- 200-250oC
- CO2 and NH3 and H2O
The materials form a ,,,,,,,,,,,which insulates against temperature rise
- carbonaceous char
Application thickness can vary between typically ,,,,,,,, ;
- 4-15mm
These materials can be repaired and brought back to required thickness after exposure ,,,,,, ;
- to fire
Epoxy intumescent is applied over a,,,,,,,,, , but the materials must be tested and approved for use together ;
- primed surface, (normally zinc phosphate epoxy)
The tests are carried out at ,,,,,,,,,approved laboratories and are usually a ,,,,,to test for adhesion between the primer and PFP ;
- NAMAS/UKAS
- lap shear test
