Polypropylene serves as the most practical and serviceable construction material available for chemically-resistant custom process equipment. Unlike lined or coated materials, it is acid-resistant throughout its thickness. Its use in building freestanding tanks, liners, covers, containment systems and ductwork for the metal finishing and other industries has been common since the 1970’s. It has gained an ever-widening acceptance in many other applications.

As a maintenance consideration, Polypropylene repairs do not require extensive downtime, as is always the issue with tanks made of rubber-lined steel, brick or fiberglass. Usually, the repair of a polypropylene tanks allows you to restart operations within hours of the arrival of our Field Service Crew, not weeks or even days. There are no multiple-trades involved. All you’ll need is CEPC LLC.

Most common process acids have little or no chemical effect on polypropylene. Nitric Acid will tend to oxidize a tank’s interior surface over time, making interior weld repairs and modifications more difficult. Still, the many advantages of polypropylene far outweigh these minor considerations. Carbon and Stainless Steel producers most-often specify polypropylene as their preferred tank construction material because of the following considerations:

  • COST: Initial and maintenance costs are hugely lower than lined steel
  • SERVICEABILITY: Fast, easy repairs require no curing or set-up time
  • THERMAL QUALITY: It is a excellent insulator, at 1.2 BTU-In/SqFt-Hr-degF
  • WEIGHT: It is 1/8 the weight of steel for ease of handling and installation
  • DURABILITY: The optional ‘Copolymer’ material makes impact “no problem”
Important Design Note: At CEPC LLC, we build tanks and liners with a very special structural advantage that is not available from any other vendor in our industry. Some years ago, we installed our exclusive corner fusion welding machine. For deep batch tanks, our machine will make 45-degree butt-fusion welds in all four vertical corners. On shallow continuous tanks, we incorporate our 45-degree butt fusion corner welds in the bottom of the long walls.

By definition of simple geometry, our corner fusion method produces over 140% of the material thickness in a fusion weld cross section, as compared to traditional welding methods and 90-degree square corner fusion welds. In plastic welding, butt-fusion welds are the strongest because there is no filler material in the joint. When coupled with a 6 or 10-bead extrusion backup weld, our corner fusion machine gives you a welded joint that is stronger than the parent material itself! In the case of Nitric Acid involvement, the elimination of weld exposure is extremely important to extended tank life. More fusion welds mean less chemical attack when in service.

Another CEPC LLC exclusive is our “Polyliner” protection system. It uses Non-Float Polypropylene for protection at the bottom and endwalls of tanks. Parts can then rest on the floor without causing body damage. This cost-effective method has helped many in the general batch pickling and galvanizing industries.

Polypropylene is the engineered, proven material of choice for the metal finishing industries.