<p>One of the most valuable resources that nature has bestowed upon mankind is water. Water must be filtered for several reasons to be safe to drink. Wound filters are inexpensive and disposable, perform as as pre-filters. Their performance is determined based on allowable pressure drop/flow rate. Destructive testing of wound filters using the single-pass test method is a relatively simple method adopted to find the efficiency of cartridge/candle filters. Multiple-pass test methods need a sophisticated instrumentation setup for the efficiency tests, but they are costlier. In contrast, the single-pass test requires less complicated instrumentation, with two test condition options, making it apt for lab-scale experiments. In the single-pass test operating under constant flow rate test conditions, the inlet flow rate is regulated to remain constant for the entire test duration. In the case of constant pressure drop test conditions, the pressure drop across the filter housing is controlled to remain the same throughout the test. A test rig designed earlier, trained for constant flow rate and aqueous test conditions was available. The study sought to modify it so that the same setup could work under constant pressure drop conditions, materialised by incorporating a flow-controlling valve and pressure transmitters. Experiments on the modified test setup showed a decline in the flow rate at the filter housing’s outlet, implying lower volumetric consumption of water; about 50&#xa0;L for a 2-hour test trial. The results of the study presented can benefit manufacturers of candle filters and testing equipment.</p>