DeltaFire

Tank capacity for sprinkler or hydrant systems is calculated from the fire suppression design standard being used — typically BS EN 12845 for sprinklers or BS 9990 for hydrant supplies — which sets minimum stored volume and duration based on hazard category and building use. Your fire engineer or sprinkler contractor should confirm the required litres before you order, as this isn't something to estimate. Delta Fire tanks are available across a wide range of capacities to match these calculated demands.

Fire water tanks are built to hold a static reserve that's drawn down quickly and at high flow rates when a pump or hydrant system activates, so they need robust outlet connections and structural design to cope with rapid emptying. They don't need to meet WRAS potable water standards, as the water isn't for drinking, but they must be compatible with the pump suction and control arrangements specified by your fire system designer. Delta Fire tanks are purpose-built for this duty rather than adapted from general-purpose water storage.

Yes, many Delta Fire tanks are designed for underground installation, which suits sites where surface space is limited or where the tank needs to be discreet. Below-ground tanks require correct backfill, groundwater considerations and adequately rated access covers to take pedestrian or vehicle loading as needed. Above-ground options are also available where excavation isn't practical or where visual access for inspection is preferred.

Fire water storage tanks generally fall outside water company wholesome water regulations since they're not connected to the potable supply for consumption, but building control will want to see the tank sized and installed in line with the relevant fire suppression standard as part of your fire strategy sign-off. If the tank is fed from the mains via a break tank arrangement, backflow prevention will still be required at that connection point. It's worth checking requirements with your building control body and insurer early in the design stage.

The tank is fitted with a suction outlet sized to match your pump set's flow requirements, along with fill, overflow and low-level alarm connections as specified by the system designer. These connections and their positioning need to be agreed before delivery, as retrofitting large-diameter outlets on site is far harder than specifying them up front. Your sprinkler contractor or fire engineer will typically provide the connection schedule for us to work to.

Fire water tanks need suitable manway or inspection covers to allow periodic checks of water quality, sediment build-up and internal fittings, which is a requirement under most fire suppression maintenance regimes. For underground tanks, covers should be rated for the loading they'll see, whether pedestrian or vehicular, and positioned with clear access for maintenance personnel. We can advise on cover sizing and placement based on your site layout at the enquiry stage.