Air-operated diaphragm pumps require a compressed air supply to drive them. If this does not already exist it can be very expensive to install. Even the best-maintained air supply systems are inefficient with at least 30% air leakage. The energy costs of supplying air for an AOD are much higher than for a Watson-Marlow peristaltic pump.
Air pressure limits the discharge pressure – it just stops pumping beyond its limits.
Changing pumped fluid is complex as cleaning an air-operated diaphragm pump is difficult – often requiring a complete strip-down. Watson-Marlow LoadSure pumps offer one-minute maintenance with pumping elements. Change the tube, create a new pump.
A diaphragm failure can result in pumped fluid escaping uncontrolled through the air vent ports. Watson-Marlow LoadSure pumps have fluid management with leak detection and controlled waste drain.
The difficulty in accurately controlling air supply makes the AOD a poor choice for metering duties.
Even double diaphragm pumps have a high level of pulsation.
As with all diaphragm pumps, AODs rely on ball valves. These do not work well unless there is positive back pressure to close them between cycles. They are prone to abrasive wear and can clog with crystals, fibres or solidifying fluids such as inks.
While the initial purchase cost is lower, Value for life costs are much higher due to energy and maintenance costs.
Watson-Marlow peristaltic pumps win on all counts:
- Lower running costs
- No air supply needed
- No valves to clog and wear
- One-minute maintenance
- Easy to clean
Find out more about the Watson-Marlow range