How to Choose a Liquid Diaphragm Pump for Higher Backpressure
Compare liquid diaphragm pumps with the same nominal flow but different pressure capability. See how backpressure and tubing connections affect selection.
Watch the standard- and high-pressure liquid pump comparison
Why equal free-flow ratings do not mean equal pump performance
A pump should meet the required flow at the resistance of the installed circuit. This comparison introduces DPL30 and DPL30H, both listed at 300 mL/min free flow, with different pressure capabilities and connection arrangements.
Compare the operating point
The overview lists 100 kPa for DPL30 and 600 kPa for DPL30H. These pressure specifications are separate from the 300 mL/min free-flow rating; they do not mean either pump delivers that flow at its maximum pressure.Match the tubing connection
DPL30 uses hose-barb connections, while DPL30H uses threaded connections. Check the mating fitting, tubing, seal and assembly space before replacing one with the other.Include the full liquid circuit
Filters, valves, narrow tubing and the receiving chamber all contribute to backpressure. Compare the flow-pressure curve at the required operating condition, then test with the intended fluid and temperature.
Compare standard- and high-pressure liquid pump configurations
The first pair compares brushed versions; the brushless alternatives are also available below. Select the motor and electrical interface separately from pressure capability. Use the individual specifications and drawings for the exact configuration.