The best way to select a tube is to first decide which materials are chemically suitable, and then choose the one which best meets the physical demands of the application. For maximum tube life, use a large bore tube at low speed. For maximum flow rate use the largest tube at maximum speed. For maximum accuracy, use a small bore tube at maximum speed. Suction lift depends on the tube restituting fully before the advance of the next roller. If it does not, the flow rate will be reduced. For maximum suction lift or pressure, use the smallest practicable bore size of tubing and run the pump at the slowest possible speed Always make an immersion test before choosing a tube material for critical applications. Immerse a short length of the tubing (always available from Watson-Marlow Bredel or its distributors) in a closed container of the fluid for 48 hours, and then examine it for signs of attack, swelling, embrittlement or other deterioration. | 
