Dreno Compatta Sewage Pumps

Typical Applications for the Dreno Compatta

The Compatta range is most commonly specified for sewage lifting stations in residential and light commercial buildings — situations where gravity drainage is not possible and wastewater must be pumped upward to reach the public sewer. This includes basement WCs, lower ground floor bathrooms, and new-build annexes where the drainage level sits below the street. The pump is installed in a below-ground sump chamber, and the vortex impeller allows it to handle toilet waste, paper, and typical household solids without the risk of blockage that would affect a standard drainage pump.

In commercial settings, the Compatta is regularly used in restaurants, hotels, and retail units where wastewater from kitchens and welfare facilities needs to be pumped to an above-ground drainage connection. The cast iron construction is suited to continuous duty cycles, and the availability of three-phase 400V models makes it straightforward to specify for commercial electrical installations. For sites handling food preparation waste, the 50mm solids passage of the 4/55 Series provides additional tolerance for fibrous material.

The range is also used on construction sites and renovation projects as a temporary installation to manage groundwater and dirty water in excavations, where the robust cast iron body and submersion depth of 20 metres give it greater durability than a plastic-bodied pump would provide. For guidance on calculating the flow rate and head your installation requires, see our article on understanding pump head and flow rate.

Frequently Asked Questions

What is the difference between the 22/32 Series and the 4/55 Series?

The two sub-series differ in motor output, maximum head, and solids passage. The 22 and 32 models have 0.56kW and 0.75kW motors respectively, a maximum head of 8–10 metres, and will pass solids up to 40mm. The 4 and 55 models step up to 1.1kW and 1.5kW motors, reach heads of 13–15 metres, and handle solids up to 50mm. For a straightforward domestic sewage lifting station with a head under 10 metres, the 22 or 32 Series is usually sufficient. For larger commercial installations or any application requiring more head or a greater solids passage, the 4 or 55 Series is the correct choice.

What is a vortex impeller and why does it matter?

A vortex impeller creates a spinning flow of liquid within the pump casing without the solids passing through the impeller blades directly. This non-contact pumping action dramatically reduces the risk of blockage when handling sewage containing solids, fibrous material, or wipes. It is the reason the Compatta can handle raw sewage reliably where a standard centrifugal pump would clog. The trade-off is slightly lower hydraulic efficiency compared to a channel impeller, but for sewage duty the reliability advantage is the priority.

Do the manual models need a separate float switch?

Yes. The M and T manual models have no automatic start/stop function — they run when switched on and must be stopped manually, or wired to an external float switch or control panel. For any unattended installation, either select an automatic model (TG or MG suffix) which includes an integrated float switch, or pair a manual model with a suitable float switch wired to a control panel. Running a manual pump unattended without float switch protection risks dry-running the pump if the sump empties, which will damage the mechanical seal.

Can the Compatta handle toilet waste and sanitary products?

The Compatta will handle toilet waste, paper, and soft solids up to its rated passage size (40mm for 22/32 Series, 50mm for 4/55 Series). It is not a grinder pump and will not macerate solids before pumping — it passes them through intact. Sanitary products, wet wipes, and other non-dispersible materials should not enter the system, as with any sewage pump, since these are the primary cause of impeller blockage in field use. If your installation is likely to receive non-dispersible materials regularly, a grinder pump is the more appropriate choice. Our guide to choosing a sewage pump covers this in detail.

What outlet size and connection do these pumps use?

All Compatta models use a 2-inch BSP threaded outlet. This is a standard fitting size compatible with most UK site pipework. The outlet is horizontal on the pump body, so allow for the appropriate elbow or swept bend in your installation design if you are connecting to vertical rising main pipework.

Are Dreno Compatta pumps available with ATEX approval?

Dreno does offer ATEX-approved variants of some Compatta models for use in potentially explosive atmospheres, such as fuel storage facilities or certain industrial environments. If your installation requires ATEX certification, please contact us on 01252 515169 or email sales@aesrewinds.com to discuss requirements before ordering.

Not sure which Compatta model is right for your installation? Our team can help you work through the flow rate, head, and supply voltage requirements for your site. Browse our full range of sewage and wastewater pumps or get in touch on 01252 515169 — we’re here Monday to Friday.