A slurry is defined as solids in liquid.

It is impossible to define when the quantity and size of the particles becomes too much for a mechanical seal because the design of some mechanical seals incorporate non-clogging seal features.

If the fluid you are pumping is a mixture of a liquid and a solid we have a useful formula to calculate the specific gravity of a slurry:

  • Sm = Specific gravity of the mixture or slurry
  • Sl = Specific gravity of the liquid phase
  • SS = Specific gravity of the solids phase
  • C= Concentration of the solids by weight

The formula for the concentration of solids by weight (Cw ) is:

Here is an example of a typical mixture:

You have a water and solids slurry. The water is a liquid with a Specific Gravity of 1.0 and the % solids by weight is 30%. The solids having a Specific Gravity of 2.7, then:


  • Speed limits for slurry pumps, S074
  • Slurry pumps, S062
  • Slurry sealing, SA010,
  • Non clogging seal features, N008


  • On February 17, 2018