When a leachate pump model is discontinued, the manufacturer’s replacement is often dimensionally identical, but you should still confirm the duty point before ordering. For two discharge pumps at a leachate treatment plant, the replacements were an end-suction model that was the current equivalent of the old one, and a smaller pump whose head had to be re-confirmed with the operator.
The challenge: old records, new questions
The old pumps had run for many years. The only record of what they were meant to do was an old order. A pump supplier asked to quote a like-for-like replacement warned that the operating data came from that order, decades old. The first reply even named a different liquid, dilute hydrochloric acid, before being corrected to leachate.
The approach: re-check every figure
Pump 1: current equivalent of an old type
One line’s pump was an old SHS-type model. The supplier confirmed that its current equivalent, a 316 stainless steel ESHS 65-160 end-suction pump with a hard-faced mechanical seal and a 5.5 kW motor, is dimensionally identical, so it fits the existing base and pipework. It was quoted at 60 m³/h and 20 m head.
Pump 2: head changed on review
For another line, the first supplier quotation gave a head of 4 m. After discussion, the plant’s quotation was for a head of up to 8 m, still at 60 m³/h, on a 2.2 kW motor at 1,450 rpm, with a 316 stainless steel casing and a special seal. A spare impeller was offered separately.
| Pump | Flow | Head | Hydraulic power | Motor |
|---|---|---|---|---|
| Line A | 60 m³/h | 20 m | about 3.3 kW | 5.5 kW |
| Line B | 60 m³/h | up to 8 m | about 1.3 kW | 2.2 kW |
These figures are the flow multiplied by head and gravity. The motors are about 1.7 times the hydraulic power, so the 4 m to 8 m change matters: at 8 m, the 2.2 kW motor still has headroom, but little more than that.
A larger 316 pump elsewhere
A third example, an ESHS 65/160 with an 11 kW motor, Viton seal and 316 stainless steel casing, was quoted for a different line, showing how one family covers different duties by impeller trim and motor size.
Why it works
A pump is defined by flow and head. A change of head moves the operating point, the motor load and the pump’s efficiency. Checking the duty is cheap compared with fitting a pump that is too small or too large. A hard-faced seal is a good choice for liquid that may carry grit.
What to consider for your own project
- Measure the current duty, with a gauge or flow reading, if records are old.
- Ask for the replacement’s dimensions against the old pump.
- Name the liquid correctly on the order.
- Buy a spare impeller if a trim may change.
- Check motor voltage and frequency for the site.
For a higher-head example, see our post on selecting a submersible pump for landfill leachate.
FAQ
Is a replacement pump always a direct fit?
Not always. Ask the supplier to confirm dimensions, as was done for the ESHS replacement.
Why check the liquid?
Materials and seal choice depend on it.
What is a hard-faced seal?
A mechanical seal with hard faces that resist wear from abrasive particles.
Can a smaller motor be used?
Only if the duty has been confirmed and leaves a margin.