Piston Pumping Fundamentals

Coating

This involves application of material by either spray or dipping. Coating applications use 2-ball and 4-ball pumps.

Dispensing

Moving a low-to-medium viscosity fluid from one location to another. 2-ball and 4-ball style pumps are the most frequently used in transfer applications.

Extrusion

Involves using a piston pump to apply medium-to-high viscosity materials. Typical extrusion applications require accessories like rams and fluid regulators to meet customer requirements. Chop-check and 2-ball pumps are used in extrusion applications.

Transfer

Moving a low-to-medium viscosity fluid from one location to another. 2-ball and 4-ball style pumps are the most frequently used in transfer applications.

Ratio is the effective area differential between the air motor piston and the lower end plunger rod. An 11:1 ratio indicates the pump air motor piston has 11 times the effective area of the fluid handling piston.

Higher ratio pumps produce higher fluid pressures which allows them to either move higher viscosity fluids or transfer fluids longer distances.

1. At 100 psi of inlet pressure, an 11:1 pump produces 1,100 psi of fluid outlet pressure.
2. A 23:1 pump would produce 2,300 psi of fluid outlet pressure, given the same air inlet.

UHMW-PE (Ultra-High Molecular Weight Polyethylene) – Anall-purpose packing material that provides excellent abrasionresistance. Commonly used with inks, acids, and some solvents.

PTFE Compatible with all fluids. Provides excellent corrosionresistance but minimal abrasion resistance. Commonly used withcorrosive chemicals, ketone, acids, and room-temperature vulcanizing(RTV) materials.

Leather Commonly used in combination with UHMW-PE packings forexcellent sealing and abrasion resistance. UHMW-PE and leather aremost often used when pumping inks.

Staggered Combining packing seals made of different materialcombinations can often maximize service life by utilizing thestrengths of both materials.