3.2.21 Plastic pumps

Plastic pumps

Plastic pumps are most suitable when used for pumping acid, alkalies and corrosive salt solutions and other aggressive chemical agents. They are used in many different industries including, chemical and petrochemical, pharmaceutical, oil refinery, electroplating, printed circuits, electronic, photography, military, water treatments, biotechnology, paper mills, textile, sugar plants, food processing, dairies and many others.

A general review of physical properties, temperature and corrosive resistance of various plastic materials must be considered before selecting suitable material but usually pumps are partly or mainly made from PVDF, Polypropylene, ABS, Noryl, Teflon or PVC.

Larger sizes of plastic pumps must, because of the physical properties of the plastic material, be equipped with an outer reinforcement casing to carry the pipeline loads and to absorb forces due to the fluid pressure — figure 3.221.

This outer casing is not necessary for smaller pumps or if the particular plastic material has suitably good physical properties. Since the fluids handled are of a dangerous nature, great care must be given to the type of shaft seals. The
construction generally being similar to that of the ISO standard pumps.

Plastic pump with surrounding reinforcement casing.