Tonkaflo Pumps

Tonkaflow pumps are a multi-stage centrifugal pump designed to be the ideal pump for use in reverse osmosis and other water treatment applications. Superior in high pressure applications and flow rates up to 500 gpm.


  • SS Series – Stainless steel components with thermoplastic (Noryl) internals.
  • AS Series – All stainless steel (304 and 316) construction.
  • QS Series – Vertical in-line used primarily in medical equipment and sound-sensitive applications.

Membrane Housing

304 and 316 grade stainless steel options are available in the 8-inch and 4-inch housings depending on the preference for corrosion resistence or material preferences. Osmonics recommends the following to specifically avoid pit corrosion by high chloride

Osmonics side port membrane element housings are some times piped to a common manifold, but more typically they are piped together using the four-port configuration rather than a separate manifold. There are some limitations to the flow that should be pu

Benefits of Stainless Steel Housings:

  • Rugged durability and exceptional tensile strength
  • Smooth uniform surface prevents potential microbial
  • Contamination or poor membrane element fit
  • Uniform diameter to ensure snug membrane element fit
  • Weigh less than FRP or PVC housings
  • Stainless less doesn’t warp, weep, puncture or crack

Why 4 Port?

This created a lot of stainless steel high pressure piping and a lot of work whenever you wanted to change the membrane elements. So, engineers started to design a side port entry to minimize the number of connections on the endcap and the work required to open a housing for a membrane change. The first evolution of this was the 2-port housing.

Continuing evolution of the product , the drive for cleaner designs, reduced costs, and product improvements led to the 4-port housing creation. The idea was, ‘why not move the high pressure piping manifold inside the housing and eliminate extra stainless steel piping.’