Rim Seal Area Fire Protection System (RAFP)
Rim seal area for floating roof tanks detection & extinguishing system
As known, for floating roof tanks the fire risk is accumulated at the rim seal area because of that’s construction nature. Vapour of the stored product creates a highly flammable mixture with ambient air. Any external ignition source in any point at this area may result with a fire which may affect all the seal area if not detected & suppressed in earlier stages. Most important firefighting action to fight against a rim seal fire is to detect the fire. The rim seal area is hidden by the tank wall and that is not so easy to detect the fire at the earlier stages with conventional detection systems. At conventional extinguishing systems are triggered by means of several detectors and detection logic to operate some valves etc. to start the active extinguishing systems.
C.S.I. RSFP system is self-sufficient to detect any fire at the exact point with its pneumatic detection system and extinguish simultaneously discharge of the extinguishing agent to the rim seal area with pre piped discharge nozzle/piping system.
C.S.I. RSFP systems are used to protect approximately every 40 meters of circumferential length of rim seal area. Modular systems are located over the floating roof with an overlapping manner of the detection line to cover all the area. After installation of the detection and the extinguishing lines, system should be pressurized by using the pre load kit available on request. As the functioning principle of the system, the pressure tank and the detection tubing will be pressurized to a predetermined value. The “differential pressure multivalve” is a special valve which is kept normally close by the balance pressure of the tank inside and the pneumatic detection line. The pneumatic detection line consist of a thermoplastic tube with certain certifications to burst under specific pressure and temperature level. In case of detecting a fire at the rim seal area, the pneumatic detection tubing will burst and change the balance of the differential pressure valve which triggers the pneumatic actuated extinguishing agent control valve to open. When the discharge valve is open, the extinguishing agent is discharged through the nozzles located along the circumference of the tank which extinguishes the fire and creates a protection blanket.
As an option, the pressure vessel could be pressurized in case of any pressure failure at the detection line by an external cylinder systems. Please consult to C.S.I. for further information.
Rim Seal Area Protection system pressure vessels are object to PED certification with notified body. C.S.I. S.r.l. is holder of H1 certificate according to PED and in possession to mark the products with CE mark.
Technical specifications of the system
|Nominal Vessel Capacity||250 Liters (depending on request)|
|Construction code||EN 13445 or ASME VIII Div.1|
|CE/97/23 PED Classification||Category IV - PS.V ≥ 5000 bar liters|
|Vessel design temperature||-10 / + 90 °C|
|Design pressure of the Vessel||28 bar g|
|Working pressure limits of the Vessel||0 – 25 bar g (Vessel to be pressurized at 20°C)|
|Protected length along the circumference of the tank||40 meters|
|Maximum distance between & quantity of the nozzles||2 meters & total 20 nozzles|
|Max vertical distance between the nozzles and rim area||0.4 – 0.6 meters above the seal|
|Approximate flow rate of single nozzle||15 l/min|
|Discharge time||30 / 40 seconds|
|Max total weight of the pre-loaded system||380 kgs.|
|Pressure Vessel||P355NH (EN 10028-3) or ASTM A 516 Gr B Carbon Steel|
|Roof for sun & rain protection||P355NH (EN 10028-3) Steel|
|Pneumatic actuated extinguishing agent control valve||Brass with Nickel Plating|
|Extinguishing Agent control valve actuation line isolation valve||Stainless Steel body & internals|
|Differential pressure multi-valve||Valve body & sphere: Stainless Steel, Actuator: Stainless Steel casing|
|Pneumatic detection line low pressure switch (ATEX)||Casing Stainless Steel|
|Pneumatic detection tubing||Thermoplastic UV resistant|
|Safety Valve||Stainless Steel AISI 304|
|System pressure gauge||Casing Stainless Steel|
|Vessel low pressure switch (ATEX)||Casing Stainless Steel|
|Lifting lugs & Roof supports||Carbon Steel|
|Name plate support||Carbon Steel|
|Junction Box for signal transmittal (ATEX)||Aluminum Cast|
|Earthing Plate||Stainless Steel|
|Extinguishing drainage and loading valve||Stainless Steel body & internals|
|OPTION 1||External: Epoxy Poly urethane paint > 300 microns|
|Internal : Epoxy Bitumen Paint > 300 microns|
|OPTION 2||Hot dip galvanization & Natural finish|
|OPTION 3||Hot dip galvanization|
|Epoxy Poly urethane paint > 50 microns|