When one pump isn’t enough or downtime isn’t an option, ZWL pumps run in parallel or duty/standby. Here’s how to set that up sensibly.
| Flow Rate | 8–800m³/h |
|---|---|
| Head | 10–80m |
| Power | 1.5–75kW |
| Inlet / Outlet Diameter | DN25–DN300 |
| Material | Cast Iron,SS304，SS316L |
Plenty of sites run more than one ZWL direct-coupled self-priming sewage pump — either to move more than a single pump can, or so a spare is always ready if one drops out. Both setups are straightforward, but each has a couple of things worth getting right.
The most common multi-pump setup is duty/standby: one pump runs, a second sits ready and takes over automatically if the first trips or is pulled for service. On a station that can’t afford downtime — a municipal sewage pit, a critical process sump — this is the sensible arrangement.
A good practice is to alternate which pump is the “duty” one (many controllers do this automatically), so both share the running hours and wear evenly, and so the standby pump doesn’t sit idle so long it seizes.
Run two pumps into a common discharge and you get more flow — useful when demand outgrows a single pump, or during peak/storm loads. One caution: parallel pumps add flow, not head, and system friction rises with total flow, so two pumps don’t simply double the output. Size the pipework and check the duty point so both pumps sit in a sensible part of their curve.
ZWL Direct-Coupled Self-Priming Sewage PumpGet the pipework right and a ZWL self-priming pump primes fast and moves solids cleanly. A practical guide to suction and discharge pipe sizing.
ZWL Direct-Coupled Self-Priming Sewage PumpA self-priming pump holds liquid inside — which can freeze in winter. Here’s how to protect a ZWL pump in cold weather so it primes when you need it.
ZWL Direct-Coupled Self-Priming Sewage PumpWhich ZWL pump parts wear, and which spares to keep on the shelf? A practical guide to impeller, mechanical seal, sealing ring and bearings.
