Diaphragm Pump


These air operated pumps are ideally suited for handling abrasive slurries because the liquid velocity through the pump components does not exceed piping velocity, so there is very little abrasive wear.

Cost considerations limit their usefulness to about 250 gpm (58 m3/hour). If you need more capacity you can run several of these pumps in parallel.

You can also use them for:

  • Dry powders.
  • The pumps have no rubbing parts and the velocities are low, so these pumps can be used for liquids with viscosities up to 50,000 SSU.
  • They also work well in shear sensitive material such as latex

Although classified as displacement pumps, they are not positive displacement pumps because their discharge pressure is limited by the plant air pressure, and air pressures above 125 psi (8.5 bar) is not always available.

They have many other advantages:

  • No heat builds up. They can be used in a confined area.
  • No bypass or relief valves required as with other displacement pumps.
  • No alignment.
  • Self priming from a dry start.
  • No seals or packing needed. Zero fugitive emissions.
  • Power is used in proportion to the capacity they are pumping.
  • Can run dry forever.
  • No close tolerance parts.
  • Easy to repair.
  • Explosion proof.

The challenge to diaphragm pumps is to provide a lower air consumption while maintaining peak flow to provide better effeciencies

One SCFM of compressed air requires approximately 0.21-kwh to generate.
To determine the cost of compressed air:

  • Volume of air x kwh per unit x cost per kwh = Cost 1 scfm x 0.21 x $ 0.08 = 1.7¢ per hour