DAB EsyTwin - 64 GPM 92 psi 2-Pump Booster System with Dock and 5 Gal Tank, Self-Priming, 4.2 HP, 1 in NPT

A complete two-pump pressurisation system for a residence or apartment building that needs more than one E.SYBOX can deliver. The two units associate wirelessly — no external controller, no hardwired master — and stage sequentially: one pump modulates to hold pressure at light demand, the second joins when demand climbs, for up to 64 GPM. Either can lead, and lead priority rotates on runtime so wear is shared. Configure both active for full flow, or one as reserve so the building never loses pressure if a pump faults. The E.SYTWIN dock sets both pumps on one compact manifold, and a 5-gallon tank lengthens runs and reduces cycling.

Because each pump carries a share of the flow, each sits higher on its own curve — so at any working flow, the pair holds more pressure than one pump would at that same flow. Only the shut-off ceiling at zero flow is fixed, unchanged at 92 psi. The performance table below is read at the flow the pair delivers.

Group figures follow DAB’s parallel-pump method: each pump carries half the total flow, so the pair’s curve is the single-pump curve read at half the system flow. DAB publishes no certified combined table for the twin; size against the system curve rather than by doubling a single-pump maximum.

The figures below are the pressure the system adds at each total flow, both E.SYBOX units running. That is what the pump curve measures — the impellers do not know what pressure is already on the inlet.

Drawing from a tank, cistern or well — nothing arrives with pressure, so what the system adds is what you get. Read straight through: 21 GPM comes out at 81 psi.

Fed by a city main — the system adds on top of what already arrives, and the controllers hold up to 85 psi total. Incoming pressure buys you more flow, not more pressure.

DAB positions the twin for apartment buildings up to about 9 floors and 17 apartments under its average-value selection assumptions. Actual sizing must be analysed for each installation.

The E.SYTWIN dock supports four inlet/outlet arrangements so the building connections can enter from either side: both left (A), diagonal right-in left-out (B), both right (C), or diagonal left-in right-out (D). Same-level cross-dock combinations are not permitted — each valid arrangement pairs the designated inlet manifold with the designated outlet manifold. Unused ports are capped with the included plugs.

Both pumps connect to the free DAB DConnect app, which gives setup, status and live operating parameters from an iOS or Android device.