Hydrocyclones & Separators Support

Download the Hydrocyclones Troubleshooting Guide

McLanahan's Hydrocyclones Troubleshooting Guide can provide information on what to do if you have excessive solids in your feed, how to remove entrained air in the pump's suction, how to replace a loose or damaged lining and more.

Hydrocyclones & Separators Maintenance

How often should I check the internal surfaces?

Wear in Hydrocyclones/Separators is unpredictable, but it can be expected that the apex will wear the fastest of all the components. Once wear is detected at the apex, it can be reasonably expected that the bottom of the lowest cone section and the feed box will begin to show wear and should be inspected commensurate with the ongoing wear rates. The coarser the fractions and the more crushed materials being processed, the faster the wear will be. Note that there is typically a spiral wear pattern tracking down the inside surfaces. As a rule of thumb, check for wear within the first month of operation.   

In the case of the Separator, are there additional maintenance checks to be made?

The Separator is differentiated from a Cyclone by the addition of the Underflow Regulator (the rubber flap valve at the bottom of the Separator) and the Overflow Pipe. The regulator should be checked once a week for integrity; the siphon valve on the siphon-controlled overflow pipe should be checked also.  Typically, wear will be unnoticeable in the Overflow Pipe until operations problems appear.

What different materials of construction are available?

The shell of a Hydrocyclone is typically a mild steel fabrication with a high-quality natural rubber lining cold-bonded to the steel. The apex on a Hydrocyclone is a steel fabrication with a loose rubber conical liner. A Hydrocyclone vortex finder is a rubber-lined steel fabrication.

The shell of a Separator is typically a mild steel fabrication with a high-quality natural rubber lining cold-bonded to the steel. On a Separator, the apex is an aluminum casting with bonded liner. The vortex finder in a Separator is cast polyurethane. The underflow regulator is of hand-fabricated rubber construction.

For either configuration, polyurethane liners are available where the chemistry requires it. Ceramic linings are also available where coarser crushed materials are being handled.   

Operational Best Practices

What can you do if your Separator is sending too much useable fines to waste?

This can result for several different reasons:

  • The siphon valve is either adjusted closed too much or blocked causing too much siphon. Often, an elliptical rocking of the unit is associated with choking.
  • There is too much feed going to the Separator causing it to choke and misplace recoverable particles. Typically, keep the feed below 23% solids by weight.

When should I replace the apex?

Wear inside the apex will cause the Hydrocyclone to have a more dilute underflow and potentially contaminate the product with finer fractions. A good rule to remember: With the water goes the fines, so keep a watch on a gradually finer product stream and check the apex before it gets unacceptable. 

What can be changed on a Hyrdocyclone to affect performance?

  • Inlet pressure will alter the cut of a Hyrdocyclone (higher pressure results in more fines captured). A vortex finder diameter change can be appropriate in this case.
  • Installing or removing the feed box extension will result in a finer cut and a coarser cut respectively.
  • Cone angles can be between 10 degrees and 40 degrees; each has the effect of changing the performance.
  • For all these changes, consult our Process Engineers for assistance.  

Can I change the angle of the Hyrdocyclone from vertical to inclined?

A Hyrdocyclone can be mounted at an incline without penalty. This can be useful when trying to save height. Make sure that the body of the Hydrocyclone can free-drain. An example is that the centerline of a 20-degree cone would be at an angle of 15 degrees to the horizontal, resulting in a 5-degree drain. 

McLanahan Corporation recommends you keep certain spare parts at your facility in the event of a breakdown or to perform repairs.

Part Name


Splash Guard 1
Splash Guard Clamp1
Vortex Finder1

How-To Videos

How To Change An Underflow Regulator In A Separator™

The part of the Separator™ that sees the most wear is the underflow regulator. Watch the video to learn how to change an underflow regulator, or click here for step-by-step instructions.

Looking for more info on Hydrocyclones?


Need Some Help?

Our customer service team is here to help you 24/7. We can ship you parts, send field service technicians to your site and answer any questions you have. Whatever you need, we are here for you.