There are a number of Fluoropolymer materials that are “generically” called Teflon
(“Teflon” is a Dupont Registered Trademark)
The most common are PTFE, FEP, PFA, etc.
They each have different properties.
So you need to know how it will be used in order to choose the right material.
STAMP is an acronym which is commonly used in the Hose & Tubing Industry
The Inside Diameter (ID) and also the wall
thickness if specified
The temperature of the chemical passing through
as well as the temperature of the environment.
How is it being used?
What is chemical and concentration of the material
passing through the tubing.
To what Pressure / Vacuum will the tubing be
Are you looking for Smooth Bore or Corrugated tubing?
(Corrugated tubing will allow a smaller bend radius, but it is obviously not as easy to clean, and usually requires special end connectors.)
What type of End Connection will be required/installed?
Unless you are looking for large quantities of tubing, I suggest you contact either a local industrial hose supplier or plastics supplier. They should be able to help you work out what product will do the best job for you.
Some manufacturers’ websites that might be of interest:
Page Int'l http://www.pageintl.com
Heat shrink tubing is a different type of product but would be subject/limited by similar issues.
Medical applications would be a whole other category of products with a different set of specific additional concerns.