Underground Construction - July 2018 - 26

REHABTECHNOLOGY
Jeﬀ Awalt | Executive Editor

PSE&G's 36-Inch Gas Main Renewal Reﬂects
Growing Capabilities, Conﬁdence

CIPL Project Sets
World Record

T

The roughly half-mile stretch
of South Orange Avenue framing the Seton Hall University
campus is one of the busiest
spots along New Jersey's County Route 510, and some of its
heaviest congestion is hidden
beneath the freshly paved lanes
that link Newark to the state's
scenic northwest.
When Public Service Electric & Gas (PSE&G) identified
numerous joint leaks in an
aging cast-iron gas main, the
Newark-based utility faced
the additional challenge of
a crowded and complex substructure. Since its construction in the 1950s, the 36-inch,
high-pressure main had become
embedded in a maze of utilities,
including water, telephone,
electric, cable, storm drains and
multiple sewer lines.
"A lot of short-term emergency repairs had been made
to the pipe as it deteriorated
over the years, and the mass of
infrastructure that had built up
around it left us with very few
options for a long-term, permanent solution," said George
Ragula, distribution technology manager at PSE&G. "We
had already identified 15 joint
leaks along a 2,000-linear-foot
section of this feeder main,
so it was essential for us to
develop a plan and take immediate action."
Tapping its own deep experience and working in collaboration with Wenonah, N.J.-based
Progressive Pipeline Manage26

JULY 2018 | UConOnline.com

ment (PPM) and Karl Weiss
Technologies of Berlin, Ragula
and his PSE&G team completed a permanent renewal of the
36-inch main using trenchless
methods and a cured-in-place
liner (CIPL). The group overcame a series of challenges -
both planned and unexpected
- to set a new world record for
the largest diameter gas main
renewed with CIPL.
The project adds to a string
of successful CIPL gas main renewals in ever-increasing sizes
using the Karl Weiss Starline
product. The growing track
record for larger-diameter projects, combined with an influential university study on the
lifespan of Starline liners, has
sparked a long-awaited surge in
demand for PPM, the exclusive
North American licensee since
2002.

Absence of options

Along with all of the other
structural limitations below
South Orange Avenue, the presence of a 12-inch, low-pressure gas main running parallel
to the 36-inch, high-pressure
main added to the congestion,
making it practically impossible to consider replacement of
the cast iron pipe. Insertion of a
smaller-diameter, higher-pressure plastic pipe within the
host pipe also was ruled out as
a viable option because PSE&G
couldn't afford to lose capacity
on the critical feed.
PSE&G also considered exca-

vating and encapsulating all of
the leaking joints over a period
of time, but concluded that this
was not only impractical, but
would have a major negative
impact on traffic flow and the
surrounding community. The
utility had already identified 15
leaking joints and knew it eventually would have to repair all
of the joints. With joints spaced
at 18-foot intervals across the
entire 2,000-foot stretch, the
approach was deemed cost-prohibitive.
"We knew that re-laying
it wouldn't work because we
couldn't find a clear lane, and
we concluded that there really
was only one viable option that
was cost-effective and offered
minimal disruption, and that
was trenchless renewal of the
pipe using CIPL," Ragula said.
PSE&G made the decision
in June 2017 to proceed with
CIPL renewal, using the adjacent low-pressure main as a
relay to maintain service during
low summer demand, but a detailed game plan was needed to
ensure the project was finished
before cold weather arrived.

Critical game planning
CIPL has been used for U.S.
water main renewals since the
1970s, but the first gas application using Starline liners was
in 1999. PSE&G was one of the
Right: Starline cured-in-place liner
coming off the drum, guided as it
enters the host pipe.
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