FELUWA MULTISAFE® double hose-diaphragm pumps
for abrasive, aggressive and toxic media

In-built piston compressors

When using standard air vessels or hose-diaphragm pulsation dampeners, the attainable residual pulsation depends on the compressed gas volume above the liquid column within the pressure vessel. With air vessels, however, there is a constant loss (solution) of gas at the contact surface of the conveyed fluid which reduces the dampening volume accordingly.

The compensation of this loss within the air vessel requires periodic refilling by means of costly monitoring and filling devices equipped with shut-off and control units. For this purpose, FELUWA has developed an ingenious and most effective “in-built piston compressor”. With each piston stroke, it feeds a small quantity of gas or atmospheric air into the discharge air vessels.

The attainable pressure of the pump piston compressor is always considerably higher than the maximum pump pressure. This ensures that the conveyed fluid cannot flow back to the pump piston compressor under normal working conditions.

Hose diaphragm piston pump with discharge air vessel and in-built piston compressor.


Working principle

With each return stroke of the piston rod, a small volume of filtered air (or gas) is sucked into the compressor chamber via a valve. With the forward stroke of the piston rod, this air volume is fed via the non-return valve into the air vessels. This procedure is repeated with each stroke of the pump and is only active when the pump is operating. By this means costly starting and stopping of air injection devices is fully eliminated and the available air volume within the air vessels is always maintained at an optimum level.

The attainable residual pulsation is reduced to a minimum. At high pressure and/ or applications which require frequent and fast filling of the air vessels, the suction end of the in-built piston compressor may additionally be fed by compressed air.