Integrating Corzan® CPVC Into Existing Copper and Other Metal Piping Systems
The simplicity of working with Corzan® CPVC is renowned by installers of plumbing and HVAC piping systems. Once trained in proper techniques, they come to find that most projects can be completed with only a few handheld tools. So when the need arises to integrate CPVC pipe into existing systems of copper, stainless steel, carbon steel or galvanized steel, the same installation basics make the job cost-effective and straightforward.
Likewise, engineers have two priorities when they are planning an integration – to minimize downtime and maximize value by keeping installed costs low while setting up the system for extended life. Thanks to Corzan CPVC’s durability, corrosion resistance, high temperature resistance and compatibility with water disinfection chemicals, that consideration of extended service life is easily met.
Fortunately, CPVC – and Corzan Piping Systems in particular – can be specified for integration into metal systems, unlike some other plastics that can suffer degradation from proximity to copper ions. Due to its chlorinated structure, Corzan CPVC has inherently good resistance to oxidizers, and its amorphous structure and high glass transition temperature make Corzan CPVC much less permeable to oxidizers and metal ions than polyolefins and other semi crystalline materials. It is especially important to know this for water distribution system projects. Depending on the pipe size, several different joining technologies are available for mixed-material integrations.
Integration of Corzan CPVC to a Metal/Mixed System with NPT Threaded Fittings
If the piping is two inches or less, the piping can be placed into service right away with threaded connections/adapters. Many kinds of small pipe adapters are available on the market, such as male and female metal-to-CPVC transition fittings. As the two fittings are threaded together, the opposite tapers force thread friction, with the outside diameter of the male getting smaller towards the end of the fitting and the inside diameter of the female narrowing with depth. This method forms the seal without the use of a gasket.
Integration of Corzan CPVC to Metal/Mixed System with Flange-to-Flange Connections
When the piping is 2-1/2 to 6 inches, the transition from one material to Corzan CPVC often occurs using flanges. ASME B16.5 150# flanges of different materials will stay strong, and maintain the same pressure rating as the pipe and fittings, so long as they are properly bolted together.
- Measure the sections of piping to be replaced at the nearest flanges, often located at shutoff valves. More piping may be removed than absolutely necessary, but this method generally creates the strongest bond for Corzan CPVC.
- Prefabricate the replacement piece and its flanged joints wherever possible before bringing down the system. This will leave only a simple process to move the lightweight piping into place and bolt the flanges.
- Remove the metal flange and pipe to be replaced.
- Bolt the new flange to the one attached to the system.
Integration of Corzan CPVC to a Metal/Mixed System with Mechanical Couplings
If the piping is larger than two inches up to 12 inches, the method for integrating Corzan CPVC into a metal or mixed piping system involves mechanical couplings. If the correct couplings and compatible gaskets are selected and installed properly, the metal system will experience no deration beyond the operating range of the piping system. Mechanical joining involves no cure times, which is ideal for alterations and other work in larger facilities, as drying time is eliminated, and plumbing system shutdown time is dramatically reduced. Follow these steps for working with mechanical couplings:
- Measure the sections of piping to be replaced.
- Cut the Corzan CPVC to the correct length and groove the new piping, according to the following correct steps.
- Groove the metal pipe according to the specification of the transition coupling being used.
- Apply a thin coat of compatible lubricant to the sealing lips of the gasket.
- Insert the grooved end of the pipe into the Corzan CPVC end of the coupling.
- Tighten the coupling evenly until metal-to-metal contact occurs at the bolt pads.
- Insert the valve into the metal end of the coupling until contact with the center leg of the gasket occurs.
- Complete the same process with the opposite coupling end.
- Visually inspect the bolt pads at each joint to ensure sufficient contact.