How to Select a Chemical Transfer Pump: A Six-Step Method

Most chemical pump failures were specified, not manufactured. The selection conversation determines reliability years before the pump exists. Here is the sequence we run on every enquiry — use it to interrogate any supplier, including us.

Step 1: Name the liquid precisely

Not 'acid' — hydrochloric acid, 32%, at 45 °C. Concentration and temperature change material compatibility completely; 'sulphuric' at 10% and 98% are different pumps in different materials. Include trace contaminants and the cleaning chemicals the pump will see.

Step 2: Fix the duty point

Flow and total dynamic head — static lift plus friction losses at the target flow. A pump selected on 'about 20 metres' gets throttled into an early grave when reality is 32. If you cannot calculate the head, give us the pipe run and elevations; we do the arithmetic.

Step 3: Establish the suction condition

Flooded suction, suction lift, or a below-grade tank decides the construction before anything else. Lift duty points to self-priming or vertical designs; a standard end-suction pump on suction lift is a priming problem repeated daily.

Step 4: Select the material of construction

Match every wetted component — casing, impeller, shaft, seal faces, O-rings — to the liquid from step 1. This is where non-metallic PP/PVDF construction usually beats exotic alloys on both corrosion life and cost. Verify against a resistance chart at your actual temperature, not a generic table.

Step 5: Choose the sealing strategy

Mechanical seal or seal-less magnetic drive? Hazardous, fuming, toxic or crystallising liquids justify seal-less. Large, hot or solids-bearing duties justify a quality mechanical seal with the correct faces and flush. This one decision sets your maintenance calendar for a decade.

Step 6: Price the lifecycle, not the pump

Purchase price is typically under 20% of ten-year ownership cost. Energy, seal replacements, downtime and spares dominate. The cheapest quote is frequently the most expensive pump.

Send us steps 1–3 and we return steps 4–6 as a written selection — that is the enquiry form on this site, and the response comes from an engineer, not a sales desk.