GRPFire Combination Units

It's a self-contained fibreglass (GRP) tank that combines the water storage vessel for an automatic sprinkler system with a dry compartment for the pump set, all in one weatherproof unit. Because it sits outside the building envelope, it frees up internal plant space and simplifies installation — the tank, backflow protection and pump housing arrive as one plug & play package rather than several separate items to coordinate on site.

A type AB air gap is a physical break between the incoming mains supply and the stored water, preventing any possibility of contaminated water being siphoned back into the mains. It's the required backflow protection method for Fluid Category 5 risks, which fire suppression storage falls under. Every Fire Combi unit is manufactured with this air gap built in, so there's no need for separate backflow prevention devices or valves.

Capacity is dictated by your fire strategy or sprinkler design calculation — typically based on the hazard category (BS EN 12845 or LPC rules for the property type) and the required duration of flow at design pressure. Your fire engineer or sprinkler contractor will specify the exact litreage needed, and we can match that against our range of standard capacities and dry compartment sizes. If your figure falls between standard sizes, get in touch and we'll advise on the closest suitable unit.

Yes, that's exactly what it's designed for. The GRP shell is fully weatherproof and the tank incorporates integral insulation to protect stored water and the pump compartment from frost, so it can be positioned externally, away from the main building, without additional shelter or cladding. It still needs a level, stable base and reasonable access for maintenance, but no weatherproof housing is required.

The unit requires a flat, level, load-bearing base — typically a concrete slab or compacted stone base designed to take the full weight of the tank when filled with water plus the pump equipment. Ground conditions, access route for delivery, and any lifting requirements should be assessed before the unit arrives, as these units are large and heavy once positioned. It's worth confirming base specification with us or your groundworks contractor at the design stage rather than after ordering.

Yes, Fire Combi units can be pre-fitted with a range of connection sizes and positions to suit your sprinkler pump set and pipework layout, reducing on-site fitting work. Let us know your pump manufacturer's inlet/outlet requirements and preferred connection points when ordering so the unit arrives ready to connect. This is part of what makes the range genuinely plug & play rather than needing site modification after delivery.