Firefighting Foam Storage Guidance - Angus Fire

1 Firefighting foam Storage Guidance This Guidance document applies Shipping Containers z M ild Steel (uncoated): Not to the following natural protein recommended for synthetic or foam concentrate may be stored in based, fluorinated and fluorine- its original shipping containers. It is fluorine-free foam concentrates. free foam concentrates from available in 20 & 25 litre black plastic Ferrous metal ions can poison the Angus Fire: Respondol ATF, drums, 210 litre (55 US gal) blue plastic foam concentrate leading to reduced JetFoam, Syndura, Expandol, drums, and 1000 litre IBCs. Containers Firefighting performance. Suitable ForexpanTridol S, Tridol Ultra, comply with UL 162 (7th Edition) and for use with natural protein-based Tridol C, Tridol ATF C, UN recommendations. However these foams, although there may be slight Tankmaster, FP70, FP350, FP600, should be regularly inspected to verify initial etching which will not affect Petroseal, Alcoseal and Niagara.

2 Their condition. In the unlikely event of the tank or contents. Natural protein leakage the foam should be decanted based foams quickly inhibit this into another clean drum, sealed and process by forming a thin protective Shelf Life tested to ensure it is still in satisfactory layer on the surface of the mild steel. condition. The maximum safe stacking Angus Fire's foam concentrates are height for 25 litres plastic drums is two z S tainless Steel: 316L and Duplex specially formulated to ensure high without pallets or 4 high with 2205 grades. Tanks with welded exceptional Storage stability as well as pallets (2 high per pallet); for 210 litre construction should have all Firefighting performance. plastic drums is 2 high (with pallets); joints treated to ensure consistent A shelf-life of at least ten years can be and for IBCs is 2 high.

3 foam containers properties close to welds. There may expected if stored properly according should not be stored or transported be very slight pitting which will not to these recommendations and this in direct sunlight. affect tank or contents. figure is based on laboratory-based z G lass Reinforced Plastic (GRP): accelerated ageing tests and history of Storage Tanks Fibreglass with epoxy resin. Not manufacture. foam concentrates are suitable for recommended for foam systems However, to ensure satisfactory transferring into bulk Storage tanks for involving pressure displacement. performance they should be sampled long-term Storage , but these should z High Density Polyethylene (HDPE). at least annually as recommended in normally be kept full, with space allowed for expansion with adequate z Polypropylene.

4 NFPA 11, which states that samples of concentrate shall be sent to the vacuum/venting arrangements. The use of zinc, galvanised materials, manufacturer or qualified authority for Particular attention should be paid to and aluminium in Storage tanks, quality condition testing. At least the "Evaporation" section overleaf. pipework, and machinery handling annually an inspection shall be made of foam concentrates should be avoided. Materials of Construction foam concentrates and their tanks or In the event that foam is being Storage containers for evidence of foam concentrates have a neutral pH replenished into an existing system excessive sludging or deterioration. and generally no corrosion problems where zinc or galvanised materials The Angus Fire foam Testing Service is will occur with metals or plastics were used in original construction, it is a qualified laboratory and will perform (except where noted below).

5 Storage advised that the system is flushed such tests on any foam concentrates or tanks should be fabricated from or be through with water and drained after foam premix solutions as required. lined with the following materials: use. Firefighting foam Storage Guidance Gaskets, seals, and bladders may be foam concentrates are suitable for z W. hen changing foam concentrate fabricated from all commonly-used decanting into small containers. stored in an existing tank, or after elastomers: Agitation and air intrusion should be commissioning: The foam system kept to a minimum if foam concentrate should be emptied of any foam z E thylene Proplyene Diene Monomer pumps are used. concentrate previously contained (EPDM) or Ethylene Propylene Rubber in it (or water used for hydrostatic (EPR) (eg. AP Rubber). Evaporation tests), cleaned, and dried prior to z B.

6 Utyl rubber (modified isobutylene) filling it with the final charge of foam If foam concentrate is allowed to (eg. Bucar, Polysarbutyl, MD551, concentrate. Particular care should evaporate freely, the water and solvent Buna N, Nitrophyl). be taken when changing foam in the concentrate will evaporate. With types. Drain down system - open z Fluoroelastomer (eg. Viton). Alcoseal or Tridol ATF C foams this all valves. Fill foam tank with water may cause a skin of polymer to form z N. itrile Rubber (butadiene acrylonitrile and allow to drain. Repeat. Backflush on the surface of the concentrate copolymer). through outlet using sufficient water which could plug proportioning as calculated to completely fill and z PTFE orifices. overflow the tank twice. Allow to Fittings in foam concentrate pumps To minimise evaporation losses, the drain.

7 Purge out all water, check and valves may be made from brass, concentrate tank should be sealed and to see foaming has ceased. If not bronze, and gunmetal. Dissimilar metals a pressure vacuum vent installed to continue to cycle through process in contact with one another (eg. a break the seal when the concentrate is until foaming has diminished. Set stainless steel tank and a brass valve) required. valves correctly. Fill slowly with foam will lead to electrolytic action. This will concentrate to minimise frothing Evaporation will also be reduced by cause galvanic corrosion of the metals. and formation of air pockets. Charge keeping the concentrate tank full. Dissimilar metals should either be foam line to furthest designated However, an ullage of 5-10% of the tank avoided or a non-conducting gasketing valve so that foam concentrate volume (eg.)

8 Expansion dome) should material should be used in the joint. is present in all pipes where it is be maintained to allow for differences required. Drain foam concentrate in thermal expansion coefficients Pipework from any pipes where drying out between the tank materials of could occur and rinse through with The choice of pipework materials construction and the foam concentrate. pressure hose reel or similar. depends on the anticipated contact Avoid ullages greater than 10%. time with the foam concentrate. For z I n normal usage of system: This If it is not possible to seal the tank, continuous contact the same materials presumes it has been designed air ventilation may be provided of construction apply as for Storage to avoid dead-legs in the system by breathers fitted with cowls. tanks (see above).

9 PVC, copper, brass, and drainage/flushing points are Alternatively a nitrogen inerting system and bronze pipes are also acceptable included to facilitate preventative comprising a nitrogen layer maintained for continuous contact. For intermittent maintenance. Judicious use of high above the concentrate at a pressure contact normal pipework materials pressure water regularly will enable fractionally above atmospheric pressure are satisfactory subject to normal pipework to be flushed and drained will reduce evaporation and ensure engineering criteria. to dry so preventing any drying that leaks are nitrogen less rather out of foam concentrate which Inlet pipework should be located at than oxygen gain. A layer of hollow could lead to the deposition of any the base of the tank to avoid excessive plastic spheres, either polypropylene solid material.

10 Drain and flush until foaming during filling. Outlet pipework or polyethylene, may be floated on the foaming diminishes. should be located above the base of the surface of the concentrate to reduce tank to prevent clogging in the event evaporation. Use of a transparent bottle filled to half of any minor sediment that might have level and shaken regularly will assist in formed or other foreign materials in the Flushing judging the cessation of frothing. tank. Storage tanks, pipework, and pumps Ensure all flushing by-products are Pipework systems should be designed that have been filled with foam managed in accordance with Angus to prevent water and other liquids concentrate or solution should be Fire recommendations. accidentally entering the tank and foam flushed with clean water and drained concentrate accidentally escaping from after use.