With methods originally developed in 1966 by a Pennsylvanian plastics company, plastic corrugated tubing came into use in the United States in 1967 as a means to transport liquids. This followed the invention by Germans of corrugation extruding machines earlier in the decade. Fluorinated ethylene-propylene (FEP) tubing offers a number of useful properties that make it ideal for certain applications. With a spiraling structure, convoluted tubing has traditionally been used for electrical conduits due to its dielectric properties. Made from “Teflon,” the brand name for the synthetic chemical polytetrafluoroethylene (PTFE), convoluted tubes made from this material also have specific uses.
Differences Between FEP Corrugated & PTFE Convoluted Tubes
One of the primary differences between FEP corrugated and PTFE convoluted tubes is appearance. FEP corrugated tubes are made from a highly-transparent fluoropolymer, while PTFE convoluted tubes – though made in various colors – are generally opaque and are usually naturally colored. As the natural color for PTFE resins is a whitish and milky color, it is at best semitransparent. Yet visual appearances are not the only difference between these two material types and their tube shape.
What is an FEP Corrugated Tube?
To produce FEP, it must go through a melting process using conventional injection molding with a screw extrusion. FEP corrugated tubing is engineered for flexibility, which enables tubes to turn sharp corners. This property makes it useful as well for other applications requiring sharp bending, allowing the tubing to follow very small bend diameters without diminishing the inside diameter. It also enables hoses made from the material to be built longer, while maintaining precise tolerances.
Other benefits of FEP corrugated tubes include:
- Acid, corrosion and crush resistance makes it useful in numerous industrial and outdoor settings.
- Chemical inertness of FEP makes it useful for transporting chemicals.
- Does not conduct electricity well, so is useful for insulation.
- Low friction coefficient makes its surfaces non-stick and easy to clean.
- Transparency allows operators to monitor materials passing through it.
- Works well in high temperature conditions, with a maximum temperature for continuous operation of 200° F (93° C).
FEP corrugated tubing is often used in factories that utilize robots. Its flexible nature provides pathways for pneumatic systems, electrical wiring or corrosive fluids that power industrial automation. As an FDA (US Food and Drug Administration) compliant material, FEP is also well-suited for food processing applications. To operate under higher pressure, it’s often reinforced with braids made from Kevlar, the brand name for the chemical compound poly-para-phenylene terephthalamide.
Applications for FEP Corrugated Tubes
FEP corrugated tubing was first used for filling bottles with liquids due to their compression capabilities. Its chemical inertness brought it into use later for paint solvents. Corrugated tubing made from FEP also offers a variety of other properties that make it work well for specific applications under certain conditions.
Applications for FEP corrugated tubes include:
- For printing roller coatings in printing plants.
- Handling corrosive and other fluids.
- Use in low-pressure microfluidic applications, such as those used for pharmaceutical experimentation and in biotechnology.
- Medical equipment that must penetrate into the body, such as catheters.
- Water disinfection or analysis via ultraviolet (UV) processes.
- When braided with stainless-steel, tubing can be used for high pressure applications.
FEP’s excellent biocompatibility capabilities make it particularly useful in healthcare settings and for processing food and drink. In these settings, its friction resistance allows for ease in cleaning, though unlike convoluted tubing it cannot self-drain.
What is a PTFE Convoluted Tube?
PTFE is more heat resistant than FEP, enabling it to be used continuously at higher operating temperatures. Additionally, it has a lower coefficient of friction than most other plastics, allowing for easier cleaning as is the case with FEP. PTFE convoluted tubes offer significant flexibility as well, though unlike FEP tubing they allow for self-draining due to the structural properties of the convolutions. Due to its chemical resistance, PTFE tubing is also used to carry both industrial and natural solvents.
Benefits of PTFE convoluted tubes include:
- Approved by FDA for food and pharmaceutical processing.
- Chemically inert when exposed to most chemicals.
- Easy to clean.
- Functions well in wide temperature ranges, from –58-450°F (–50-232°C)
- Dielectric properties make it a good insulator.
- Longer lifecycle due to UV resistance.
With the addition of cuffs, PTFE convoluted tubing can easily attach to barbed or compression fittings.
Applications for PTFE Convoluted Tubes
Since PTFE convoluted tubes offer resistance to temperature extremes and chemicals, they are useful in an array of industries. As per tubing made with FEP, when PTFE tubing is braided with stainless steel it suits high-pressure applications well. Manufacturers in the automotive, chemical, food, medical, petrochemical, pharmaceutical, semiconductor and other sectors all utilize this type of tubing.
Applications for PTFE convoluted tubes include:
- Charging various industrial cylinders with gas, including acetylene, argon, helium, oxygen and nitrogen.
- Coolant lines for electronic equipment.
- Coolant, brake fluid, fuel, oil and other fluid-carrying hoses in vehicles.
- Cooling and heating lines for injection molding equipment.
- Cooling hoses that do not conduct electricity on radio and television transmitters.
- Cylinders that provide pressurized air or oxygen in breathing apparatus.
- Dehydration lines for steam purging of refrigerant gas in air-conditioners.
- Electrical cabling in the aerospace industry
- Electrical power conduits for hot bottle stacking machines.
- Feeder lines to burners in power plants.
- Filling barrels of spirits in the distilling industry.
- Gas lines for paintball guns.
- Heat supply and transfer lines during food processing.
- Heating lines for the textile and paper industry.
- Heating supply lines in bakeries for batter mixing.
- Hydraulic lines in marine
- Light-duty hoses for transferring chemicals.
- Lines that supply milk carton manufacturing equipment.
- Lines within refrigeration units.
- Sealant lines used in canning beverages.
- Steam lines for dry cleaning and laundry presses.
- Supply lines for spray painting.
- Transferring crude oil and other petrochemicals via hoses.
Because of their dielectric properties, PTFE convoluted tubes also provide additional safety for applications where static electricity builds up and requires dissipation. Convoluted tubing can additionally be produced with thicker walls when more robust tubing is needed, or with thinner walls to ensure better flow of fluids.
FEP Corrugated & PTFE Convoluted Tubing by M.M. Newman Corp.
As an ISO 9001:2015 certified distributor for FEP corrugated and PTFE convoluted tubing, M.M. Newman Corp. supplies these and other high-quality tubing for various applications. Our company’s representatives can also advise on material selection and the best type to use for an application, depending on the need for kink resistance, flexibility or other requirements. FEP Corrugated and PTFE Convoluted tubing ranges in size from ¼” – 3” ID (6.35-76.2 mm), with either cuffed or plain ends.
AWG Sizes for PTFE Tubing
Additionally, we provide and customize tubing products, providing a wide range of American wire gauge (AWG) sizes for standard wall, thin wall & light wall PTFE tubing. Inside diameters for AWG PTFE tubing range from .010 to .33 inches (AWG size 0 and smaller). This tubing is custom and made to order.
To order or learn more about M.M. Newman’s custom-made FEP corrugated, PTFE convoluted, or AWG sizes of PTFE Tubing, contact our expert team today.