Tag Archive for: FRP Pipe

FRP and Abrasion Resistant Lining: Lined Pipe vs. Unlined Pipe

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abrasion resistant lining

This is the second in a series of blog posts discussing lined FRP pipe vs. unlined FRP pipe. The first posts discusses corrosion resistance.

In this post, we discuss abrasion resistance.

Abrasion Resistance: There is an element of abrasive wear in almost all fluid service applications.  In the concern for corrosion resistance, this abrasion element of the environment is often overlooked.  Especially for pipe subjected to high flows or where there may be particulate matter contamination (i.e. cooling water applications, river water, waste handling, etc.) abrasion design needs to be considered for all FRP pipe.

As with corrosion resistance, the resin matrix provides the abrasion resistance.  With a properly designed and selected corrosion barrier/liner, the abrasion resistance (and the pipe life) can be up to ten times greater than for unlined pipe, where the glass filaments are directly exposed to the service wear.  With unlined pipe, very rapid wear can occur, with the roving filaments being “picked” away from the surface.

Through further modifications of the corrosion barrier/liner, consisting of proper resin
selection, proper type of non-glass reinforcement, and armoring modifiers, the abrasion resistance of the corrosion barrier can be further improved.

Another compelling reason for always using a corrosion barrier/liner in FRP composite pipe is to provide the capability for changes in service environment. Even if the current service environment would not benefit from the additional protection of a corrosion barrier/liner, the addition of a corrosion barrier/liner provides insurance that future changes in the service stream can take place without concern for the life of the FRP pipe.

Perhaps the nature of the waste stream may be different five or ten years from today. Perhaps even for relatively mild cooling water or river water service, the end user may want to add treatment chemicals in the future. The zebra mussel that is attaching itself to the insides of pipe has made headlines.

The addition of a corrosion barrier/liner for pipe would provide additional abrasion resistance in removing, by mechanical means or hydro blasting, such mussel buildups.  The small additional cost for a corrosion barrier/liner can be a very inexpensive insurance policy for the future. 

The final benefit to using lined FRP composite pipe is lower in-service costs.  One of the advantages of FRP composite plastic pipe is its internal smoothness over its entire service life, especially when compared to other materials such as concrete, steel, etc.  This smoothness is translated into less friction and, thus, lower pumping cost. In some cases, even a smaller diameter pipe can be used.

Even small differences in the smoothness of the FRP pipe interior can be translated into dollar savings in electricity or fuel (for the pumps). The glass smoothness of the high resin content corrosion barrier/liner is measurably better than for unlined FRP pipe. In addition, the energy savings advantage of the resin-rich corrosion barrier/liner increases with age.

Summary:

Except for conduit, in almost all instances a corrosion barrier/liner can be economically justified for FRP composite pipe. We recommend, as a minimum, a 40 mil thick C-veil and/or Nexus reinforced corrosion barrier/liner. For moderate and severe corrosive environments, an even thicker corrosion barrier/liner should be considered.

We will be glad to work with you in selecting the best corrosion barrier/liner for their service
environment.  We are confident that “lined” FRP pipe will provide the end user their lowest cost per year of service life and, thus, their “Best Buy”.

Contact us today and we can arrange a test installation in your plant comparing Beetle Plastics abrasion resistant composite FRP pipe with your current piping and duct materials.


Improvements to Abrasion Resistant Pipe made from FRP Composites

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abrasion resistant pipeJack Mallinson of FMC Corporation’s plant in Front Royal, Virginia, working in conjunction with Beetle Plastics, then located in Fall River, Massachusetts, conducted some of the earliest work in improving abrasion resistance of FRP pipe. These original developments took place
in the late 1960’s and early 1970’s.

This work found that significant increases in abrasion resistance could be achieved by adding armoring modifiers to the resin used for the internal corrosion barrier of the pipe. In those early days, the best modifiers were various forms and grades of aluminum oxides. There were problems in getting the aluminum oxide to disperse and “wet out”. However, once the aluminum oxide dispersed, improvements of abrasion life in the magnitude of two to three times over a non-modifi ed resin were achieved. The resin matrix used in those days was typically the Hetron 197 polyester resin.

While some companies that make so-called abrasion resistant pipe still use that same filler approach and formulation from the late 1960’s, Beetle continued to find a better way. In the early 1970’s, working with the late Walt Szymanski of Hooker Chemical, Beetle Plastics made major advances in the technology of abrasion resistance in FRP composites. In an extensive series of tests conducted in conjunction with Hooker, Beetle discovered that three fabrication techniques significantly influence the resulting abrasion resistance of the composite laminate.

Type of Resin: The type of resin used in making the inner abrasion/corrosion liner of the pipe influences the resulting abrasion resistance of the pipe. Special developmental elastomeric and epoxy vinyl ester resins signifi cantly increase the abrasion service life. Beetle Plastics
worked closely with Dow Chemical and Interplastics in developing these experimental resins. The selection of the proper resin, along with specifi c resin modifi cations, increases abrasion resistance by a factor of two to three times over a standard polyester or epoxy resin.

Type of Reinforcement: Beetle also discovered, in these series of Hooker tests, that the type of reinforcements used in the matrix signifi cantly infl uenced the abrasion resistance of the inner abrasion/corrosion liner. The tests demonstrated that specific types of
reinforcements greatly improved abrasion resistance of the laminate.

Also, a specific combination of selected reinforcements was critical to obtaining the optimum abrasion resistance. As the result of that knowledge, Beetle Plastics now uses a unique combination of laminate reinforcements that help significantly improve the total abrasion resistance of the composite laminate.

Armoring Modifier: Building on the early work done with FMC, Beetle conducted extensive tests to improve armoring modifiers. Beetle succeeded in developing a new type of modifier that provides superior armoring of the FRP composite. This material compares in toughness to
basalt, which in its natural form is often used as abrasion liners for steel pipe.

Over the years, Beetle Plastics has fine-tuned the specific grades of this armoring modifier material, selecting those that demonstrate the best performance in abrasion resistant FRP composite pipe. Beetle also developed techniques to gain the optimum dispersion and wetting out of this armoring modifier within the resin. Getting this ideal resin “hook” to the armoring modifier is also an important consideration when developing the best possible abrasion resistance of FRP laminates.

In order to gain maximum abrasion resistance from FRP composite pipe and laminates, it takes careful selection of all three of the important factors (resin, reinforcements, and armoring modifiers), in the proper ratios and interactions.  Test results from this research indicate reductions in abrasion loss in FRP composite laminates to just one-tenth that of non-modified laminates. In other words, you might expect increased service life of ten times, or more, from Beetle Plastics abrasion resistant composite pipe and ducts.

But, to paraphrase an old saying – “the proof is in the pudding”. For FRP composite abrasion resistant pipe, the proof is in the service life obtained in actual fi eld installations.

In tests, control installations showed substantial abrasion wear and failure in just several months of service life. Regular six-month and annual inspections at these plants of Beetle Plastics abrasion resistant pipe and elbows (an elbow is an area of high abrasive wear) showed little discernable wear.

Beetle continues to refine our FRP pipe abrasion resistant technology. As a result, you can confidently turn to Beetle Plastics for the best FRP composite abrasion resistant piping system available.

Customers at numerous projects have achieved outstanding FRP piping service life in highly abrasive applications such as lime slurry, fly ash slurries, and the extremely abrasive bottom ash service.

Contact us today and we can arrange a test installation in your plant comparing Beetle Plastics abrasion resistant pipe with your current piping and duct materials.

Lined Pipe vs. Unlined Pipe – Pipe Strength and Structural Integrity

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lined pipe vs. unlined pipeIn earlier posts, we discussed the first reason to choose lined FRP pipe: abrasion resistance and corrosion resistance. The third major reason to choose Lined FRP pipe is Structural Integrity.  While typically the corrosion barrier/liner is not counted on for adding strength to the FRP pipe, it does enhance the structural integrity.  Depending upon the service environment, sometimes the structural properties of the SPI type corrosion barrier/liner are included in determining the pressure rating of the FRP pipe.

One of the advantages of properly designed and manufactured fiberglass filament wound composite pipe is that it will typically show signs of “weeping” through the pipe wall when over-pressurized, long before a catastrophic failure occurs.  Such weeping occurs by fluid wicking following the continuous glass roving used in filament winding.  The weakest portion of the structural wall is the glass/resin interface. The corrosion barrier/liner, thus, serves to prevent the fluid media from getting to that continuous fiberglass filament.

From a purely structural viewpoint, the ideal corrosion barrier/liner would be a rubber bag. This rubber liner would continue to stretch, allowing the structural wall to fully take advantage of the superstrong, continuous glass filaments until they actually broke.  A properly designed resin corrosion barrier/liner serves the same function allowing the structural wall to take the full load without concern for pipe wall weeping.

Contact us today and we can arrange a test installation in your plant comparing Beetle Plastics abrasion resistant composite FRP pipe with your current piping and duct materials.

Lined Pipe vs. Unlined Pipe – Corrosion Resistant Pipe

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corrosion resistant pipeIt has always been our contention that all FRP composite pipe for fluid service should have an internal corrosion barrier/liner.  Therefore, it has been our policy to supply all pipe, with such a corrosion barrier/liner.  The type and thickness of this corrosion barrier/liner will depend upon the specific service environment.  The thickness of a corrosion barrier/liner can range from a 40 mil (0.040″) for cooling water applications, to over 200 mil (0.200″) SPI type for wet chlorine gas service.

The purpose of this blog post series is to detail why we believe it is important to provide FRP composite pipe with an internal corrosion barrier/liner.

We will take each major reason and discuss in each blog post.

The first major reason to use lined FRP pipe is Corrosion Resistance.

We realize that some pipe manufacturers market a pipe without a corrosion barrier/liner (typically called unlined pipe). Interestingly, in most cases, the resins used for the unlined pipe series also have lower corrosion resistance capabilities, and lower service temperature limitations.  All pipe manufacturers provide a corrosion barrier/liner in their pipe intended for moderate to severe corrosive applications.

Since fiberglass reinforced composite pipe is typically used for applications where corrosion is a consideration, it seems only logical to use a corrosion resistant product.  In FRP composite pipe, the resin matrix provides the corrosion resistance. The higher the resin content of the laminate exposed to the service environment, the “better” the corrosion resistance. Also, within the limits of the resin system, the thicker the corrosion barrier/liner, the greater the corrosion resistance.

Unlined pipe typically has a resin content of just 30 to 40 percent in the surface exposed to the service environment.  In pipe built with a corrosion barrier/liner, the resin content is typically 80 to 90 percent.

What does all this mean to the end user?  In a filament wound composite pipe, the cost of adding a  corrosion barrier/liner is not all that great in comparison to the true cost of the pipe. The selection of the proper type and thickness of the corrosion barrier/liner can more than double the service life of the pipe.  Since fiberglass pipe is typically being bought to provide longer service life than other alternate materials, the addition of a corrosion barrier/liner can become an important cost savings to the end user, providing the lowest cost per year of service life.

Contact us today and we can arrange a test installation in your plant comparing Beetle Plastics abrasion resistant composite pipe with your current piping and duct materials.