Material selection

When selecting the material for certain pump components, it is particularly important to have a precise understanding of the collective load profile as well as a thorough familiarity with the product type. This includes static and dynamic stresses of a mechanical and thermal nature as well as stress caused by erosion, abrasion, corrosion and cavitation. The question of which types of stress constitute decisive criteria when selecting materials can essentially only be answered by someone who has many years' experience in a wide range of pump applications.

General material selection tables are available for specific types of stress. These can serve as a basic guide for determining pump materials. One of the most commonly known formats is the chemical resistance table, which lists (usually metallic) materials according to their level of corrosion resistance to liquid media.

In addition to the product form and the stress collective, financial aspects also play a key role in material selection for many applications. By contrast, in special applications such as a reactor pump for nuclear plants, the only criteria that count are those that relate to safety.

Given that pump manufacturing now relies heavily on computers, issues such as processability, availability and purchasibility are also significant factors when selecting materials.

Ultimately, the process of selecting materials for a pump component and a particular application is bound up with the expertise and responsibilities of the pump manufacturer. There is therefore often a great deal of variation between specific manufacturers.