Thermoplastic Linings for Industrial Basket Strainers
Industrial basket strainers — which are used in heavy industrial applications such as mining operations, power generation facilities, and chemical and metal refineries — are subjected to some of the harshest working conditions.
The fluids that pass through industrial strainers are some of the most corrosive liquids out there, such as seawater, pickle solutions, scrubbers, and various chemicals. This means they have to be built tough to resist their environments and remain operational.
Manufacturers address these harsh working conditions by fabricating baskets using heavy gauge PVC, CPVC, Polypropylene, or exotic metals such as stainless 316 or 304, Hastelloy C, Monel, and Titanium. Our feeling at Fluidtrol is that Polyvinyl Chloride (PVC), Chlorinated Polyvinyl Chloride (CPVC), and polypropylene baskets provide the best value because they are relatively inexpensive, lightweight, and more resistant to wear than metal baskets.
But what about the strainer bodies themselves? Can they benefit from the chemical-resistance properties of these thermoplastic materials?
While it’s impractical to try to construct industrial basket strainers entirely out of plastic, it can be used as a liner, giving manufacturers the freedom to choose other materials for structural support and exterior coatings.
That’s how we’ve engineered our industrial basket strainers at Fluidtrol. We use fiberglass for structure and reinforcement and then insert a custom thermoplastic pipe liner that meets the pressure and temperature requirements of our customers’ applications. This dual-laminated housing lets us deliver the best of both worlds: the chemical resistance of thermoplastics and the structural strength of fiberglass.
Fluidtrol industrial strainers feature three layers: a gel coat, a reinforcement stratum, and a pipe liner.
Five Durable Polymers for Industrial Basket Strainer Linings
A standard PVC liner will be suitable for most general-use cases, retaining its strength and resisting most chemicals. For applications with temperatures in excess of 140° Fahrenheit, polymers that feature greater heat resistance are available, including PVC, CPVC, polypropyelene, polyvinylidene difluoride (PVDF), and Halar.
Polyvinyl Chloride
Frequently specified for manufacturing applications, PVC has excellent resistance to acids, alkalies, and salt solutions, among others, and has the highest long-term hydrostatic strength at 73° F than any other major thermoplastic.
PVC should not be used for applications with operating temperatures above 140° F and is not a good choice for polar solvents such as ketones, some chlorinated hydrocarbons, and aromatics.
We use Class 12454B PVC for our industrial basket strainers.
Chlorinated Polyvinyl Chloride
For applications with operating temperatures above 140° F, we use Class 23447B PVC (CPVC). It has similar properties to PVC at 73° F, including the same general chemical resistance and has a Temperature Correction Factor that allows it to perform in high-temperature applications up to 200° F.
Polypropylene
Lightweight and high strength, Polypropylene is resistant to organic solvents and most acids and alkalies and maintains its pressure ratings at higher temperatures.
However, polypropylene should not be used with oxidizing acids, chlorinated hydrocarbons, or aromatics.
The polypropyelene we use for our industrial basket strainers is extruded from Group 1, Class 2, Alpha nucleated homopolymer material in accordance with ASTM D-4101.
PVDF
PVDF is a strong, tough and abrasion-resistant material. This fluorocarbon material resists distortion and retains most of its strength to 280° F. Of all thermoplastics, PVDF provides the greatest combination of strength and chemical resistance, as well as the greatest range of working temperatures.
The PVDF we use is in our industrial basket strainers is extruded from virgin, pure, unpigmented homopolymer Kynar 740 resin and meets or exceeds the requirements of Table 1 of ASTM D-3222.
HALAR
Halar (ECTFE) is a partially fluorinated polymer that is highly resistant to acids, oxidizing agents, and solvents, both in high concentrations and at high temperatures.
We recommend Halar for industrial basket strainers designed for situations with operating temperatures above 280° F but below 300° F.
Maximum pressure ratings for industrial strainer lining materials at various operating temperatures.
Conclusion
If you’re frustrated by the high costs and frequent failures of metal industrial basket strainers, take a closer look at non-metallic basket strainers lined with chemical-resistant polymers. They will cost less, last longer, and look better than traditional iron, steel, and bronze industrial strainers.
If you need more information about these types of products or have additional questions, please call us at 888-551-9115 or contact us.
