The size and nature of the solids in the liquid: The size and nature will affect the amount of physical wear on the pump and its components, and whether the solids will pass through the pump without being damaged.

It is also important to consider the chemical compatibility of the slurry with any elastomers in the pump. Once the nature of the slurry and the components of the different types of pumps have been addressed, you can select potential candidate slurry pumps for the application.

Traditionally, centrifugal pumps are used to pump highly abrasive slurries. Centrifugal pumps use the force generated by the rotating impeller to impinge kinetic energy into the slurry.

The type of application will determine whether a dry or submersible pump solution should be installed; in some cases, a solution that combines a dry and submersible pump may be the best choice. This article outlines the benefits of target=_blank title=Submersible Slurry Pump>submersible slurry pump versus dry mount pumping and shares some general rules that apply to both applications. Next, the target=_blank title=Slurry Pump Manufacturer>slurry pump manufacturer will share the following content with you.

Low slurry flow rates

What is a slurry pump?

The material of the sealing lip is chosen according to the liquid to be sealed and the rotational speed. For larger shafts, an NBR sealing lip can cope with surface speeds of up to 10-12 m/s, while an FKM lip is suitable for speeds of up to 35-38 m/s. 

As can be seen from the seal cross-section shown in Fig. 14.2, shaft seals are complex shapes that require advanced mold design and molding techniques (see Section 7.3 for discussion of fluoroelastomer molding). For some time, most shaft seals were made in the United States by compression molding. Injection molding of shaft seals is prevalent in Europe, and is being used increasingly in the United States. An advantage of compression molding is that preforms (usually rings cut from extruded tubing) are used that closely approximate the amount of stock required for the final parts, so compound waste is minimized. For injection molding, the amount of cured stock in the central sprue and runner (actually a thin sheet leading to the seal lip) is often large compared to the stock required for the final part, so the waste of high-cost fluoroelastomer may be high. Such waste is reduced in modern injection molding designs.

Because of the higher temperature resistance of FKM, this material is also chosen for applications where higher speeds play a role, which raise the temperature at the sealing lip considerably. Usually, using FKM will result in a longer life than using NBR. This compensates the higher price of FKM compared to NBR, as an FKM does not have to be replaced as frequently. The low temperature resistance of standard FKM is limited to -15 ˚C.

When the total eccentricity is excessive, the sealing edge of the seal lip cannot accommodate shaft motions and leakage may occur.
Total eccentricity is the sum of shaft runout and the housing-bore eccentricity.
Total eccentricity, shaft runout and housing-bore eccentricity are generally expressed in TIR (Total Indicator Reading).

In this guide, we will dwell deeply on oil seals and discuss everything that you need to know, such as what it is, how it works, why it fails sometimes, materials used in making it, factors to consider in choosing the right one for your application, and so on.

Variety of Oil Seals