Variable Round The Pump Proportioner

A Variable Round‑The‑Pump Proportioner is a foam induction device designed to produce a pre‑mixed foam solution for one or more foam‑making branchpipes. It is fitted to a fire pump, either as a temporary or permanent installation, and allows the operator to adjust foam induction flow through a knurled twist grip handle. The unit is compact, robust and corrosion resistant, making it suitable for extreme environments and integration with fire appliances or fixed foam systems.

It is called “round‑the‑pump” because the proportioner is typically mounted around the fire pump discharge and uses the pump’s discharge flow to induce foam concentrate into the water stream. This positioning allows the device to produce a premixed foam solution as water leaves the pump outlet, feeding foam‑making branchpipes directly.

The Delta Variable Round‑The‑Pump Proportioner itself has an induction flow range of 0 to 90 litres per minute, calibrated in steps of 9 LPM. The actual foam percentage achieved depends on the flow rate of the pump discharge and the selected induction setting, allowing operators to adjust proportioning to match the fire risk and foam concentrate type being used.