Plastic Interior Fuel Gas Piping Systems: Now or Never?

The home building industry has been focused on keeping the price of new housing “affordable” to the majority of American consumers. This market mantra has, to some degree, affected the quality of new construction. In the area of piping technology, there has been a notable movement away from metallic piping systems to either pure plastic or composite materials. This trend can be seen in the changes to the following piping systems :

• Sanitary drains: cast iron to plastic
• Plumbing vents: cast iron to plastic
• Potable water: copper to PEX
• Radiant heating: copper to PEX
• Underground natural gas service: steel to plastic

In a paper entitled “Reduction of the Installation Costs for Domestic Gas Appliances” [ref 1], the author attempts to establish a relationship between new energy efficiency standards and their impact on the number of gas appliances installed and the cost of installing the gas service. As the number of gas appliances (per living unit) declines and/or the amount of gas consumption declines (because of higher efficiencies), the cost of the piping installation becomes a major factor affecting the choice of fuel. In other words, if the cost of installing the gas piping is too high (compared to the operating savings of only a few natural gas appliances), the consumer will choose electricity over gas to reduce the initial cost of buying the home. The paper goes on to explore the cost benefits of replacing conventional steel or copper piping with PEX-AL-PEX tubing for the interior distribution of gas. The paper concludes that switching to non-metallic piping systems will help reduce the installation costs of future gas piping systems and should be actively considered for use (assuming that all safety issues can be satisfactorily addressed).

There are composite piping systems already commercially available that are being utilized in the global housing markets. These PEX-AL-PEX products are currently used in many North American homes for non-fuel gas applications such as water distribution. In addition, the use of composite tubing for fuel gas distribution in other countries may prompt these suppliers to consider expanding into the North American fuel gas market. However, there are many institutional obstacles that can significantly inhibit this process if not properly addressed through national codes and standards. This paper addresses the potential for and the institutional obstacles blocking the introduction of PEX-AL-PEX tubing products into the North American fuel gas market.