Types 20 and 20R shaft seals feature chemically inert materials in all areas and on all surfaces in contact with the liquid being sealed. Metallic components, springs and clamp ring are located outside the pump seal chamber, isolated from the process liquid.

For use with extremely corrosive chemicals, including concentrated acids and salts, strong oxidizing and reducing agents, and chemically active organic compounds commonly used on PTFE filled pumps.

The entire seal assembly and component parts employ mechanical drive to prevent slippage on the shaft or sleeve. Seal assembly is outside mounted and internally pressurized.