Two months after settling a court battle, PVC and HDPE pipe manufacturers are at war over the hearts and minds of highway engineers. These engineers, members of the American Association of State Highway and Transportation Officials, set standards for drain pipe under highways. Plastic pipe has carved a hunk of the huge market dominated by concrete and steel. Highway drainage is the fastest-growing market for high density polyethylene pipe, according to industry officials.
But a trade group, Uni-Bell PVC Pipe Association, is shining a spotlight on a test installation at I-279 north of Pittsburgh. Like cops, highway engineers hate to hear the words ``crack'' and ``pipe'' in the same sentence - but that's what happened to PE pipe in Pittsburgh. Uni-Bell officials say that, until questions can be answered about HDPE drain pipe, AASHTO should hold off on a pending move to drop the requirement for stress rating in resin for PE pipe.
Earlier this year, after Uni-Bell began publicizing information about the tests, the largest U.S. extruder of corrugated HDPE pipe, Advanced Drainage Systems Inc., sued Uni-Bell. ADS supplied pipe for the Pittsburgh test. In April, Columbus, Ohio-based ADS won a temporary restraining order that stopped Uni-Bell from distributing its interpretation of the tests.
According to ADS and its industry group, the Corrugated Polyethylene Pipe Association, Uni-Bell gave out false information. HDPE advocates say the PVC industry took information out of context, since the test - which buried the pipe 100 feet deep, far deeper than in actual use - was designed to test the pipe to destruction in the first place.
After depositions were taken, though, both sides settled the suit.
Uni-Bell won the full right to talk about the test, but the Dallas PVC pipe association lost valuable time. Uni-Bell also probably will lose this round of the war over a pending change in AASHTO standards, according to Robert Walker, Uni-Bell executive director.
``They put this restraining order on us and in effect they prevented us and all of our members from communicating anything about the cracks and the report in front of AASHTO,'' Walker said. ``They basically muzzled us at a very critical time in AASHTO's development process.''
Not now. When both sides settled in late July, Uni-Bell was free. The fall issue of Uni-Bell PVC Pipe News has 11 pages on cracking and buckling PE pipe. The PVC pipe group calls the Pittsburgh test ``perhaps the most significant buried pipe research of this decade.''
Now both sides - Uni-Bell and the Corrugated Polyethylene Pipe Association - aggressively are trying to get the attention of AASHTO bridge and materials engineers as they confirm by mail-in ballot their earlier, unanimous voice votes in favor of reconciling two standards for PE resin, the Section 18 design specification and the M294 materials specification.
Corrugated HDPE pipe makers favor the move - and both sides say it is probably too late for Uni-Bell lobbying to convince engineers to change their minds.
The change effectively would end the stress rating requirement for HDPE pipe resin, a process called ``hydrostatic design basis'' in engineer-speak.
CPPA, based in Toledo, Ohio, says Section 18 originally was based on corrugated metal pipe, and needs to be changed.
But Uni-Bell strongly opposes reconciling the two standards. Interviewed by telephone last week, Walker raised the specter of wide-spec resin - not something the PE pipe industry likes to talk about publicly.
``What they're doing is, they're buying on the open market from a broader resin specification, any and all surplus materials that might be available,'' Walker said.
The CPPA, which said HDPE pipe has been used in highways nearly 30 years, points out that PVC pipe does not have to meet hydrostatic design basis ratings.
Walker countered that all PVC pipe comes from the same base resin.
``In polyethylene, there is a wide variation of molecular weight and densities that are available,'' Walker said.
ADS and Hancor Inc. of Findlay, Ohio, are the two dominant corrugated HDPE pipe makers. Bill Altermatt, a Hancor executive and CPPA president, predicted the Uni-Bell campaign will not change the outcome. Votes made at the technical committee level generally are not overturned, he said last week.
Walker agreed - although another AASHTO vote could happen next year.
AASHTO officials were attending the Washington trade group's annual meeting last week and were not available.
The Pittsburgh research was conducted by Ernest Selig at the University of Massachusetts' Department of Civil and Environmental Engineering. When the study began in 1987, Advanced Drainage Systems sponsored it, but it was taken over by the Pennsylvania Department of Transportation. Selig found pipe cracking at the 100-foot depth. CPPA said that ``virtually all the cracks'' developed in areas where sections of pipe were coupled together, and the industry has improved its fittings since then.
Contacted last week in Amherst, Mass., Selig said Uni-Bell has conducted ``a very significant misrepresentation that was really negative campaigning.''
``The idea was to test it under types of fill far greater than anything that had been tried [before], with the idea to try and find out what the limits were,'' Selig said.
Tom King, vice president of new products and engineering at ADS, said state highway departments, including PennDOT, continue to buy HDPE pipe.
``The ultimate judge is, the pipe is still working, it's performing as designed according to PennDOT, and it's buried three times the normal depth for corrugated pipe in storm-water systems,'' King said.
Most pipe wars pit plastics against nonplastic materials, such as concrete. But two industry officials said the Uni-Bell vs. CPPA minidrama is not the first time plastics has slammed plastics.
``It's just part of a continuing battle between the different material suppliers of pipe,'' said Stephen Roe, president of Prinsco Inc. of Prinsburg, Minn. ``I think it's really dirty when people take other people's research and use it as a marketing ploy and call it fact.''
Sam Mascorro, a Dallas manufacturers' representative who runs Kraoy Inc., recalled that PVC and ABS pipe ``were constantly at each other's throats'' in the early days of plastic drain pipe. Then, PVC largely won out.
``I think this whole thing ought to be looked at in a clear light, just to see what has actually transpired,'' Mascorro said.