Maximum pressure: With the current design of the mp6 the maximal pressure to achieve is limited by the actuator. It can generate only a certain force, once this force is reached the actuator doesn’t move anymore. Due to the tolerances of the actuator this force limit is no exact value.
So far, we have experienced that – in systems of three serial connected pumps pumping water – a max pressure of 1.6 to 1.7 bar is possible. The last actuator is then strongly bulged out and moves with a very low stroke only. Adding more pumps brought no further pressure gain.
Therefore, if more pressure is needed a more powerful actuator would be the best solution. This can be achieved with a smaller diameter of the actuator. It is then generally stiffer than the larger diameter and can generate more force hence more pressure. However, as the actuator stroke goes down with actuator diameter the flow rate goes down with it. It is also possible to have a stronger actuator without changing the membrane diameter, but this will require different actuators, e.g. piezo multilayer bender or piezo stacks. We have some initial concepts here already. For more information, please contact us.
Operating pressure: The allowed differential pressure (inside pump to surrounding) is roughly 1.2 bar (120 kPa). However, we have found that pumps could withstand 2 bars too, but we can’t guarantee this as we don’t have so much data about this. However, if higher pressures are applied instantly the pump may be destroyed; slow increasing/decreasing pressure is ok.
In series connection the pumps can generate more pressure than one single pump. In such a system we have achieved 20 psi (1.37 bar or 137 kPa) without destruction of the last pump in line. But again, we guarantee only the 1.2 bar as these are tested in production.