December 2016, Vol. 243, No. 12

Features

Requesting Long-Term Strength Recommendation Becomes Simpler

The Hydrostatic Stress Board (HSB), an independent, technical-based group of voluntary industry experts, operating under the auspices of the Plastics Pipe Institute, Inc. (PPI), has reconstructed and expanded its website to expedite the listing request process and highlight the longstanding history of its board.

New content includes downloadable forms and templates to submit requests for compounds and composite plastic pipes (PPI TR-4), as well as a list of ingredients and PVC resins used for vinyl pipe (PPI TR-2) for inclusion in the HSB listing program.

Other new documents include step-by-step instructions about the submission process, reports of relevance about policies in PPI’s Technical Report (TR) PPI TR-2 and PPI TR-3, which are two key documents detailing listing requirements, an online HSB inquiry form, plus an “announcements” page to keep listing owners up-to-date on HSB activities and developments. (http://plasticpipe.org/hsb/).

“For nearly six decades, the HSB has contributed to the confidence level of plastic pipe and materials used in numerous applications including gas, municipal water, wastewater, sewer and industrial water systems,” said Tony Radoszewski, president of PPI. “The provision of extensive tools in this enhanced web section facilitates understanding about the program’s listing process and how to participate – a program providing a prominent level of qualification and affirmation about the uses of plastics in pipe systems.”

The HSB is comprised of engineers, chemists, scientists and others with expertise in thermoplastics, ingredients, processing and long-term strength testing. The board is chaired by PPI’s Technical Director Sarah Patterson.

“HSB policies define procedures for determining the long-term strength of plastic pipe compounds,” Patterson said, “and for converting this strength into an allowable design stress which, in turn, is used to determine the pressure rating of the plastic or composite pipe.”

Grades of recommendations are provided for the following:

• Hydrostatic Design Basis (HDB): ASTM D2837: compounds and composite pipe (polymer/ barrier/polymer or of all polymeric layers).

• ASTM D2992: fiber-reinforced thermosetting and thermoplastic resin for composite pipe constructions.

• Pressure Design Basis (PDB): ASTM D2837: composite pipe construction such as polymer/metal/polymer or of all polymeric layers of unique construction features.

• Minimum Required Strength (MRS) and Categorized Required Strength (CRS): ISO 9080/ISO 12162: compounds and composite pipe (polymer/barrier/ polymer or of all polymeric layer).

• Strength Design Basis (SDB): ASTM F2018: compounds intended for molding applications.

The first grades of recommendations were issued for PVC, PE and CPVC back in the mid-1960s. Over the years, the industry continued innovating and the HSB program continued support to the industry by developing policies for ingredients specific to vinyl compounds, crosslinked polyethylene (PEX) and composites used for pipe.

The HSB introduced the PPI PVC generic range composition in the 1980s and the listing program now encompasses PVDF and PA. In the future, the program will also include PP and PE-RT materials.

The program is cited in product standards developed by organizations such as ASTM International, American Water Works Association (AWWA), CSA Group, formerly the Canadian Standards Association, and certification programs such as NSF International.

“Code bodies, such as the American Society of Mechanical Engineers (ASME) and Department of Transportation Pipeline and Hazardous Materials Safety Administration (PHMSA), also cite the program due to its rigorous requirements and involvement in the industry since the early 1950s,” Patterson said.

Listing in the HSB program does not require PPI membership, as the program is a service to the entire plastics industry, hosted and managed by PPI.

“The new HSB web section reflects global reach and widespread interest in the program which has grown as seen in the proliferation of public listings, and through enquiries HSB receives to participate from many based outside of North America,” Radoszewski said. “This is a testament to the integrity and service leadership HSB and its programs represent. Through the supply of supplemental information, resources and online tools, HSB is heightening awareness and broadening credibility for uses of plastics in pipe systems, acknowledging them as excellent and reliable infrastructure solutions.”

For further information, visit www.plasticpipe.org and click on the “Hydrostatic Stress Board” menu option.