The fluid is cooled through this separation process to lower the temperature at the seal faces.
by Justin Patsey, U.S. Seal Mfg.
March 27, 2013

This lack of pressure will dry out the flush line, resulting in the possibility of the seal chamber running dry or the abrasive laden fluid making its way to the seal faces. In contrast, high pressure levels in the separator will result in abrasive laden fluid being shot directly into the seal chamber through the flush without separation where abrasives are concentrated at the seal faces. As a result, seal life could be drastically decreased.

In general, maintaining a steady differential is the most difficult part of installation. Also, as a word of caution, the pressure of fluid entering the separator must not exceed 2,000 psi on 316 stainless steel models and 650 psi on nylon models. Pressure higher than suggested psi will result in damage to the cyclone separator. Orifices can be used along the piping to allow for required flow rates and any need to increase separation. Excessive piping may make a recommended pressure balance harder to achieve. A length longer that 10 feet with a separator installed inline may set up problems with pressure loss or system backup.

This will be mostly applicable to a standard centrifugal pump. Split-case pumps must be treated differently in the use of cyclone separators. For split-case pumps, one cyclone separator may be used, but only if the pressure at the seal chambers, suction and discharge ends remains the same at all times. If pressure stability cannot be achieved, then two separators must be used—one on each seal chamber to avoid complications. In this scenario, using two smaller separators is better than complicating things with one large one.

An Added Benefit
In addition to maintenance cost savings and increased seal life, using a cyclone separator provides an added benefit. It reduces the fluid temperature because it is cooled through the separation process before being sent into the seal chamber, which lowers the fluid temperature at the seal faces. While in operation, the faces of the seal can be as high as 40 F above the pumped fluid. The temperature of the original fluid that will be introduced to the separator should not be higher than 400 F for a 316 stainless steel model and 240 F for a nylon separator to prevent risk of failure.

Cyclone seal separators are used in many applications and environments. Surprisingly, more than 95 percent of cyclone abrasive separators are used on grit/particle laden water in everyday applications. Most of the time, they are found in HVAC applications and service many high-rise structures.

They are also found on ships and/or in systems around water. A common example of this application is their use on service water pumps in power plants and utilities. In these applications, abrasive-laden water can be pulled from streams, rivers, lakes, or other bodies to cool equipment. In addition, slurry pump installations are a prime example of where a separator may be used.

Another important use for cyclone separators involves the installation and startup of new systems and equipment in plants, pipelines and most HVAC lines. They have a common place in these applications because of the foreign particles found in the systems that could be detrimental to seal faces. This may include any metal grindings or dust particles naturally found in new equipment.

Finally, cyclone abrasive separators can also be used on pumps or equipment with packing in the stuffing box. In this case, the only change would be that the flush must be aligned with the lantern ring connection. Proper alignment of this kind is usually a common practice with typical packing installations. This is required for packing to be properly lubricated.

1 Piping arrangement API Plan 31