Rim Seal Area Fire Protection System (RAFP)

Rim area fire detection & suppression systems designed to provide a rapid firefighting measure, used to detect and suppress fire events when occurring at the rim area of floating roof storage tanks, in early stages before creating a developed fire event. Worldwide studies show the causes of a fire event on floating roof storage tanks can be caused by absence of adequate detection system to trigger a fixed suppression system. RAFP systems should not be considered as a primer firefighting system to protect open top floating roof systems because of their limited autonomy. The system works fully pneumatically-mechanically and for its function, no external power is needed. The detection system consists of certified pneumatic tubing kept under pressure which bursts at a predetermined temperature and triggers off the extinguishing system via a special balancing valve. The extinguishing system consists of a pressure vessel containing premixed foam solution kept under pressure of nitrogen or compressed air thanks to special a balancing valve located on the upper part of the system. This special valve has a critical function using the pneumatic detection system's stand-by pressure to keep the system ready. When the pneumatic detection system detects a fire event, the pressure drop changes the balance of the system valve and the extinguishing agent is released from the fixed stainless steel piping and nozzles positioned at the rim area. Each RAFP system protects 40 running meters of a storage tank rim area. The system is equipped with ATEX certified pressure transmitters to supervise system readiness simultaneously. C.S.I. S.r.l. constructs RAFP vessels with CE mark.

Rim seal area for floating roof tanks detection & extinguishing system
Model RAFP

C.S.I. S.r.l. presents the new product line as means of automatic detection & extinguishing systems to be used in floating roof tanks to protect Rim Seal area.
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.

Construction materials

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

How to contact us?

Via Roma, 94 - 27041 Casanova Lonati (PV) - Italy

(+39) 0385.287.070 - 078

(+39) 0385.287.088

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