Pipe can be manufactured from all sorts of materials, sizes, and configurations. At US FUSION, we work most often with various types of plastic piping, including HDPE, PolyPro, and PVDF. 

In this article, we’re discussing PVDF. We talk about what PVDF is, how it’s made, when it’s used, and more. 

What Is PVDF? 

PVDF stands for polyvinylidene fluoride, which is a semi-crystalline, highly inert, stable thermoplastic fluoropolymer. It has a melting point of 347°F and service temperatures of up to 302°F. It boasts outstanding properties overall, such as great durability and toughness, excellent chemical resistance, high crystallinity, and good thermal stability. 

PVDF is one of the best radiation-resistant plastics available in the market, only bested by PEEK (polyetheretherketone) and polyamide. Today it is sold under different brand names with various additives and melt flow rates, all of which increase the processing capabilities and heighten properties for specific applications.

How Is PVDF Made?

PVDF resin is produced by free-radical polymerization of 1,1-Difluoroethylene (abbreviation = DFE, chemical formula = C2H4F2). The polymerization occurs in the emulsion of 50-302°C and 10-300 atm pressure. The obtained material is then processed into films, rods, tubes, and sheets.

The most common methods to produce PVDF polymer are chlorotrifluoroethylene (CTFE) or hexafluoro propene (HFP). HFP-made PVDF copolymer shows higher flexibility compared to PVDF homopolymer grades. Copolymers made by CTFE are superior even yet to polymers made by HFP. They are more flexible, have low shrinkage, and have a fantastic low-temperature performance range.

Furthermore, polyvinylidene fluoride is exposed to ionizing radiation using crosslinking, making various modifications to the thermal and mechanical properties possible. Additionally, different resins like methacrylic and acrylic rubbers have partial compatibility with the polymer.

Mechanical Properties of PVDF

PVDF has a good tensile modulus but fairs weak in the impact strength department. Rearrangements done using HFP and CTFE can help improve the flexibility and impact strength, as well as decrease the tensile modulus.

PVDF is also non-flammable and won’t drip. It is self-extinguishing and has decent resistance to UV light.

IS PVDF Acid Resistant?

PVDF exhibits excellent chemical- and acid-resistant properties. It can withstand a variety of aggressive fluids and solvents. It mainly shows impressive physical resistance toward organic and inorganic acids, halogenated solvents, and hydrocarbons.

PVDF Applications

PVDF has many applications, in all sorts of industries. Here are a few common examples. 

Electrical/Electronics

PVDF has many applications in the electrical and electronics industries, such as:

• Wires and cables in aircraft
• High-temperature wirings
• Home appliances
• Wire coating
• Industrial power control systems

Heavy Industries 

With help from common additives, PVDF’s good corrosion properties can improve its applicability to heavy industries like oil and gas, automotive, marine, and petrochemicals used for gaskets, seals, and linings. Lately, it is most commonly used in filtration equipment like housings, filters, membranes, etc.

Batteries

PVDF is also used for making separators in lithium-ion batteries, thanks to their reliable thermal and chemical stability. These membranes are in demand as the market for electric mobility will see sizable growth in the future.

Piping and Liners 

Chemical processing equipment depends on PVDF resin to make flexible piping, tubing, and liners to be used in water systems, chemical pipes, automobile fuel lines, and storage. Piezoelectric films are very sensitive transducers. They are malleable, rigid, and lightweight; thus, they can be shaped into various geometries resulting in unique and innovative applications.

Coatings 

PVDF is also used for coating and layering applications on metals like aluminum and galvanized steel. The coatings improve these materials’ chemical resistance and weatherability.

What Is Red PVDF?

PVDF red piping systems have been used successfully in outdoor applications for over 25 years. Red PVDF provides the same pressure/temperature range and chemical resistance as traditional Kynar® PVDF with no pigmentation.

Natural, unpigmented PVDF is unaffected by ultraviolet (UV) light, but is does permit UV rays to pass through it, affecting the media within the pipeline. Since UV rays pass through natural Kynar®  PVDF, chlorine or peroxide can cause stress cracks in Kynar®  components.

By adding a specific red pigment to Kynar®  PVDF, the UV light spectrum is unable to pass through the polymer. This protects the media within and eliminates the potential of UV rays to radicalize the chemicals.

Red PVDF not only protects the material chemistry but also extends the service life of the piping system. The red pigment also enables the material to better withstand weathering and outdoor exposure. 

However, red pigmented Kynar®  PVDF is not usually recommended for indoor use with high-purity systems such as deionized water, as it can potentially leach impurities into the media.

Contact US FUSION for Your PVDF Pipe & Fittings Needs

At US FUSION, we have the capabilities to supply, fuse, and install high-performance PVDF pipes and fittings. Our cost-effective solutions, comprehensive inventory, and custom services can meet any demand or project scope. Give our team a call or contact us online to get started.

Although it’s one of the oldest methods in the industry, sliplining is still a popular choice for underground pipe rehabilitation projects. Let’s take a closer look into what it is, how it works, and why it’s beneficial for a number of specialty construction applications.

What Is Sliplining?

Sliplining is a trenchless underground pipe rehabilitation technique that involves installing a pipe of a slightly smaller diameter into a larger “host” pipe, then grouting the space between the two and sealing the ends. This process helps to restore the structural integrity of the existing pipeline, and helps to prevent the need for a more costly, time-consuming, and labor-intensive pipe replacement.

6 Steps of the Sliplining Process

The sliplining process can vary depending on a number of factors, from field conditions to pipe materials and host pipe conditions. However, it most commonly follows a six-step process, which we’ll outline below.

1. Inspect the Host Pipe

The first, and arguably most critical step, of the sliplining process is to inspect the condition of the host pipe. During the inspection, you’ll assess the level of pipe deterioration, which is critical in determining how feasible the sliplining procedure may, or may not, be. In some cases, a host pipe inspection is done manually, but the preferred method is to use remote controlled closed circuit television (CCTV) equipment to inspect the pipe. High definition cameras inside the pipe allow you to inspect the existing pipelines safely.

2. Clean Out the Host Pipe

After you’re done with inspection and you’ve determined that sliplining is a feasible solution, you need to thoroughly clean and clear out the host pipe. This prepares the pipe for lining installation and can be accomplished using a variety of tools and methods. Some of the most common pieces of cleaning equipment include plugs, cleaning buckets, water jets, and pipeline pigs.

3. Join the Carrier Pipe(s)

Before you can install a carrier pipe into the host pipe, you’ll have to join various sections together to reach your desired length. These sections are usually welded together using butt fusion technology. Bell and spigot pipe can also be used, and the joints can be pushed together during installation.

4. Access the Host Pipe

As a final step before installation can begin, you need to access the host pipe via two small excavations, commonly known as the entry and exit pits. The areas of these excavations serve as the beginning and end of your liner installation.

5. Install the Carrier Pipe

Once you’ve done everything to prepare both pipes, you’re ready to install! You can install the carrier pipe by either pushing or pulling it through the host pipe until it reaches its intended placement. Then, in some cases, a 24-hour resting period is required following the installation. If necessary, you can use one of several ways to restore lateral pipe connections.

6. Restore the Terminal Connections and Grout the Annular Space

The final step of sliplining is to restore connections at the terminal ends of the carrier pipe and grout the annular space surrounding it. Not only does this help stabilize the new liner, but it also helps ensure that the pipe doesn’t experience any substance leakage that could potentially harm the environment.

Once your newly lined pipe is fully grouted and stabilized, you’ve completed the sliplining process. However, it’s best to keep an eye on how the new parts are performing for a couple of days, just to make sure everything still goes as planned.

4 Key Advantages of Sliplining

The sliplining process dates all the way back to the 1940s, but it’s stuck around for good reason! And with newer systems and technologies available each year, the process has only become more efficient over time.

If you’re in need of an underground pipe rehabilitation, sliplining is one of your best options. Here are a few reasons why:

• Affordable – When compared to a complete pipe replacement, the cost of a sliplining procedure is considerably less expensive.
• Efficient – With the help of an experienced technician and innovative technology, sliplining is a fast and simple process — helping you ensure your operations are back up and running with minimal downtime and environmental concern.
• Less excavation – Sliplining involves much less excavation than a full pipe replacement. This means you’ll have to worry about far less disruption, waste, and cleanup.
• Long-lasting performance – Sliplining is guaranteed to repair any deteriorating pipes and restore them to full capacity, helping you remove any risks of corrosion or leakage for years to come.

Want to learn more about our sliplining capabilities at US FUSION? Check out our downloadable brochure!

Need to rehabilitate your underground piping system? Choose US FUSION. With decades of experience in pipe rehabilitation, our team has a long history of applying the latest technologies, construction methods, and safety practices within our operations. Complete your project with us and discover why we’re the best choice in the industry. Request your free quote today.