Features & Benefits
Overview
CORZAN™ Industrial Systems: technology and service proven in over 40 years of demanding industrial use.
Developed in 1958, post-chlorinated polyvinyl chloride, or CPVC, has been offering the process industry superior corrosion resistance, mechanical strength and excellent life-cycle economics in a single package. Today, as Corzan® CPVC, this same material provides industry with longer service life, lower maintenance, and improved process utilization compared with traditional materials.
The availability of a full line of Corzan™ process components enables engineers to take advantage of these unique benefits throughout entire industrial systems. Corzan™ Industrial systems also offer the process industry comprehensive engineering services. Specialists are available to provide project assistance on topics such as material capabilities, specifications, and design recommendations.
To ensure the maximum performance of your process application, take advantage of the technology and experience behind Corzan™ Industrial Systems.
What is Corzan® CPVC?
Chlorinated polyvinyl chloride (CPVC) has become an important engineering thermoplastic due to its relatively low cost, high glass transition temperature, high heat distortion temperature, chemical inertness, and outstanding mechanical, dielectric, and flame and smoke properties. CPVC was first commercialized in the early 1960s and has since proven its value in a variety of industrial applications in which a high use temperature and excellent resistance to corrosive chemicals are desirable. Besides pipe and fittings, many other industrial fluid-handling products are available in Corzan® CPVC including pumps, valves, strainers, filters, tower packing, and duct, as well as sheet for fabrication into storage tanks, fume scrubbers, large diameter duct, and tank lining.
Conceptually, CPVC is a PVC homopolymer that has been subjected to a chlorination reaction. Typically, chlorine and PVC react according to a basic free radical mechanism. This can be brought about by various approaches using thermal and/or UV energy for initiation of the reaction. A generalized mechanism for the free radical chlorination of PVC can be schematically represented as follows, where RH denotes PVC.
CPVC produced in such a manner can be quite varied structurally depending on the chlorination method, conditions, and the amount of chlorine reacted. The chlorine content of base PVC can be increased from 56.7% to as high as 74%, though typically most commercial CPVC resins have 63% to 69% chlorine. As the chlorine content in CPVC is increased, the glass transition temperature (Tg) of the polymer increases significantly. Also, as the molecular weight of base PVC is increased, there is a smaller proportionate increase in the Tg at an equivalent level of chlorine.
The CPVC resin manufactured from this free radical chlorination reaction is not processable without the addition of additives. These additives may include, but are not limited to, stabilizers (heat and UV), impact modifiers, pigments and lubricants. The quantity and combination of these additives enhances many of the CPVC resin’s inherent properties, while easing its processability.
The family of these various compound formulations comprises Corzan® CPVC.
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Mechanical Strength
When non-metals replace metals in process applications for corrosion reasons, the mechanical strength of the system becomes a key design consideration. In order to ensure safe and reliable operation, non-metals must provide sufficient mechanical strength to meet design criteria such as:
- Maximum operating pressure
- Strength at elevated temperatures
- Equipment service life
- Structural integrity
Many non-metals do not have the tensile strength to meet
the pressure requirements of process applications, especially
at elevated temperatures. However, Corzan piping systems are
pressure rated for operation up to 200°F (93°C). Moreover,
Corzan piping systems can be expected to maintain their pressure-bearing
capabilities for 50 years and beyond.
Chemical Resistance
Many chemicals encountered in the process industry aggressively corrode most metal equipment, resulting in process leaks, flow restrictions, and ultimately premature failure. Corzan™ Industrial systems are chemically inert to most mineral acids, bases and salts, as well as aliphatic hydrocarbons. In addition, these systems are not subject to galvanic corrosion. As a result, Corzan™ Industrial Systems can replace traditional materials in many applications and provide longer service life, lower maintenance costs, and help ensure environmental compliance.
Of course, actual performance of any material depends on specific
service conditions. We have tested Corzan® CPVC with
hundreds of chemicals at various temperatures, stress levels
and other process conditions to assure material performance
in many common process applications. The recommendations are
published in the Chemical
Resistance Bulletin (CZ-3B) for your reference. Comprehensive
chemical resistance testing services are also available for
less common situations. So on your next project, contact us
for the very latest test data or to discuss the corrosion
requirements of your specific application.
Please click on the following links for information on specific
chemicals.
Cost Comparison
In order to provide both the corrosion resistance and mechanical strength to meet process design requirements, most materials are altered to compensate for inherent weakness. For example, steel piping is often lined with non-metals, resins are reinforced with glass fibers, or exotic metal alloys are developed. These changes will significantly increase the installed cost of a project.
Corzan™ Industrial Systems inherently have both the corrosion resistance and mechanical strength required for many process applications at a total installed cost lower than carbon steel. And when other life-cycle factors such as operating expenses, maintenance costs and equipment service life are considered, Corzan™ Industrial Systems are the obvious choice.
In fact, the following diagram gives you an idea of how well Corzan™ Industrial Systems compare with other materials when measured against three important criteria: chemical resistance, tensile strength, and total installed cost.
