How Plumbing Materials Are Affected by Changing Requirements

As water chemistries and homebuyer preferences change, plumbers may need to re-evaluate current practices and materials. Here are some of the changes to be aware of when selecting plumbing materials.

Changing Water Treatment Practices

For the last several years there has been a trend in municipal water treatment toward chlorine dioxide as an alternative to chlorine. According to public health professionals, chlorine dioxide is more effective than chlorine and chloramine disinfection against microorganisms, and is also highly effective at killing viruses. Even those municipalities that haven’t switched may be increasing the amount of chlorine in the water supply to accommodate growth in the distribution network.

The result of these changes is a higher Oxidation Reduction Potential (ORP) of the water flowing through residential pipes. That can be a problem for PEX plumbing systems due to their inherent vulnerability to chlorinated water.

According to the Plastics Pipe Institute, PEX may experience accelerated chlorine degradation at ORP levels above 825 mv. Chlorine dioxide alone can drive ORP levels above this threshold and disinfectants aren’t the only substance that contributes to ORP in the water supply. Dissolved oxygen, metal ions and salts also increase ORP. As a result, ORP levels above 825 mv can be  expected to become more common.

Choosing a plumbing system that is inherently immune to chlorinated drinking water provides protection against changing water conditions. FlowGuard Gold CPVC is the only residential plumbing system that is immune to chlorinated drinking water.

Increasing Demand for Luxury Showers

Luxury showers are trickling down from high-end to mid-market homes and not all materials are equally equipped to support the growth of this feature.

When installing luxury showers, the flow within and between the various loops must be properly balanced. Whether using flexible or rigid piping, that requires equal lengths of pipe connected with elbows and tees. For the simplest designs, expect to use at least eight fittings per installation and be prepared for the effect this may have on pipe sizing.

The insert fittings used in PEX plumbing systems restrict flow and create larger pressure drops at each fitting than the socket fittings used in copper and CPVC. Even so-called “full flow” PEX fittings have a pressure drop six times that of a CPVC socket fitting in a ½” 90-degree elbow.

Due to the larger pressure drop and the number of fittings required, the only way to ensure sufficient pressure in a luxury shower using PEX is to upsize the loop piping and the branch line by one or two sizes, increasing the total cost of the feature.

FlowGuard Gold CPVC will always provide better flow and pressure, frequently enabling smaller pipe sizes than PEX. It is often possible to meet shower system pressure and flow requirements with ½” CPVC pipe within the shower assembly, allowing builders to deliver this coveted feature at a lower cost.

Prioritizing Plumbing System Sustainability and Efficiency

Embodied energy is a sustainability metric that is becoming more important to builders and engineers seeking materials that minimize greenhouse gas emissions in their manufacture and transportation.

Plastic plumbing materials generally have a lower embodied energy than copper, and FlowGuard Gold CPVC has a lower embodied energy than PEX. In fact, according to the NIST BEES database, the operation of a FlowGuard Gold CPVC plumbing system emits nearly 1 ton less carbon into the atmosphere than a PEX plumbing system over the life of a small house.

FlowGuard Gold CPVC also has a lifecycle assessment that provides an objective, third-party and quantitative analysis of the system’s cradle-to-grave environmental impact. In addition, it is the only residential plumbing system certified by the Home Innovation Labs National Green Building Standard (NGBS).

The goal of improving plumbing system sustainability is also impacting plumbing system design, particularly in those developments where hot water recirculation systems are required to save water.

Like high ORP levels, these systems can create conditions that accelerate degradation in PEX piping. As a result, some PEX material manufacturers and model codes limit water velocities in hot water recirculating systems using PEX to 2 feet per second. That can dramatically reduce flow rates across the system and may require upsizing the piping to compensate for the reduced velocities, negating the water-saving benefits of a recirculating system.

FlowGuard Gold CPVC reliably supports velocities of 8-10 feet per second in hot water recirculating systems, eliminating the need for upsizing and allowing the full benefits of the system to be realized.

Remote or mini manifolds represent another opportunity to conserve water. PEX mini manifolds are often installed in locations too far from the fixtures they support, requiring long branch lines that negate their benefits and add to project costs. Converting to the FlowGuard MultiPort enables CPVC manifold designs that actively minimize the length of branch lines to help realize the desired sustainability benefits.

Up-skilling the Labor Force 

Consistent housing demand is driving an increase in skilled labor development as companies recognize the risk of being overly dependent on unskilled labor that limits their ability to take advantage of lower-cost and higher-performing plumbing systems. As they increase their focus on up-skilling, they are finding resources that enable flexible and time-efficient skills development, including some targeted to Spanish-speaking plumbers. Lubrizol Advanced Materials also provides on-site project support to aid contractors in transitioning to FlowGuard Gold CPVC.

Future-Proof Plumbing System Design

As plumbing system requirements continue to evolve, some materials and designs will prove better able to handle change and deliver reliable and cost-effective performance. FlowGuard Gold CPVC is inherently immune to chlorinated drinking water and uses socket fittings that don’t restrict water flow, allowing this system to perform reliably in changing conditions and making it the best choice for future-proofing plumbing system design. To learn more, read our brochure.