Wednesday, June 6th, 2012 8:06 am
By Matt Klaus
NFPA Journal®, May/June 2012
In June, a new edition of NFPA 13, Installation of Sprinkler Systems, will be presented at the Association Technical Meeting at NFPA’s Annual Conference & Expo in Las Vegas. The NFPA 13 technical committees have spent many hours reviewing hundreds of concepts and discussing their merits for inclusion, or elimination, from the next edition of the standard. The 2013 edition of NFPA 13, along with NFPA 13R, Installation of Sprinkler Systems in Residential Occupancies Up To and Including Four Stories in Height, and NFPA 13D, Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes, contain a number of changes, some of which will be met with certified amending motions (CAMs) at the technical meeting. The following topics highlight just some of the issues in store for the new edition.
1. CPVC Compatibility
The interaction between chlorinated polyvinyl chloride (CPVC) piping and hydrocarbon- or petroleum-based materials used in the installation of building systems has created a problem that has become more prevalent over the past five years. The issue comes down to a chemical incompatibility that is known to cause chemical stress fractures in the piping. These stress fractures can cause leaking pipes and, in some instances, failures at fittings and pipe connections. Examples of this incompatibility include the installation of CPVC pipe downstream of steel pipe that has been protected with antimicrobial coatings, and CPVC pipe that has come in contact with oils used for cutting steel pipe. The increased frequency of failures is linked to the increasing number of systems that combine CPVC with hydrocarbon- or petroleum-based materials or processes.
During the development of the 2013 edition, however, the Technical Committee for Sprinkler System Installation Criteria discussed the concept of compatibility and accepted new language aimed at addressing the issue. The new language requires that, where corrosion inhibitors are used in combination systems that include coated steel pipe and CPVC pipe, the coating must be tested for compatibility with CPVC. Furthermore, the new requirements state that when CPVC pipe is used in combination systems using steel pipe, cutting oils and lubricants used in the fabrication of the steel piping shall be compatible with CPVC materials. These changes are designed to provide guidance on two of the major culprits associated with chemical incompatibility failures in CPVC piping.
Read the full article on NFPA.org.
As this issue has developed, some CPVC pipe manufacturers have instituted compatibility programs to highlight materials that are known to be chemically incompatible with their products. While the presence of these programs and the lists of incompatible products have become an invaluable resource to the industry, NFPA 13 remained relatively silent on this issue in the 2007 and 2010 editions.