Hydrocarbon Processing - December 2021 - GP-7

MAINTENANCE AND RELIABILITY
Looking beyond processing efficiency
to optimize operations
A. BOZICK, Victaulic, Easton, Pennsylvania
When facility owners think about plant optimization, the
emphasis often is on maximizing throughput and, in many cases,
that means focusing on processing equipment. While production
efficiency is essential to profitability, there are other contributors
to optimized operations-including reliability, availability
and sustainability-that apply to every facet of operations.
Utility piping and fire safety systems, which are essential to
safe and continuous operations, can have a considerable impact
on plant uptime, illustrating just how critical they are to maintaining
productivity.
Scope of impact. Piping for utility and fire safety systems often
makes up more than one-third of the total piping in a gas processing
facility and includes a broad range of systems from utility
air, compressed air and instrument air, to nitrogen, inert gases,
lube oils, glycol and water.
A newbuild LNG facility requires all of these utility and safety
systems. Taking into account only some of these essential functions,
that could amount to thousands of linear feet of pipe, including
small-diameter pipe for fire safety systems and large-bore
piping systems in excess of 24 in. for water and glycol, inert gas
and air. Pipe material can be carbon steel, stainless steel or nonmetallic,
in applications that require flexibility or chemical resistance
and in operations where wide temperature variations occur.
To date, joining methods for these piping systems have included
welding and flanging for steel pipe and heat fusion for
HDPE, but the inherent drawbacks of these approaches are
significant, and all of them make installation and maintenance
costly and time-consuming.
Considering a different approach. Although gas processing
facilities have relied on flanging and welding for steel piping in
utility systems, these joining methods are not ideal and often
are not cost-effective. The shortcomings are well known, but
there is a reluctance to move away from a solution that works.
Achieving greater efficiencies, however, means working in a
different way and recognizing the value of a proven solution.
For more than a century, grooved mechanical joining solutions
have been used across pipe materials and sizes to provide
a solution that mitigates risk, maximizes productivity and
minimizes construction schedule. This proven technology,
adopted in a variety of chemical and energy sectors including
chemical, petrochemical and LNG, is changing the way piping
systems are designed, installed and maintained.
The coupling design is simple and consists of four basic
components: grooved pipe, coupling housings, bolts and nuts,
and the engineered elastomeric gasket. The gasket engages the
full pipe end circumference, fitting securely into the grooves to
create a unified joint, which is then enclosed by the coupling
housings and bolted on. The housings are installed using simple
hand tools, and as the bolts and nuts are tightened, the elastomer
gasket creates a triple-seal effect on the pipe ends. The gasket
sealing lips press down onto the pipe ends when the system
is pressurized, creating a leak-tight joint.
The couplings, which can be installed up to 10 times faster
than other joining methods, require only a visual inspection to
verify proper makeup. If the coupling needs to be reinstalled,
the process only takes a matter of minutes. Couplings are manufactured
as rigid or flexible joints for a range of applications and
can be installed on nearly any size pipe.
Installing grooved couplings is straightforward because assembly
requires only standard hand tools. On a recent project,
more than 120 pipefitters were trained to install mechanical
grooved couplings in less than 20 minutes and were immediately
able to execute the installation. On average, even for these
first-time installers, it was possible to install the grooved mechanical
system in half the time it would have taken to weld.
Furthermore, the visual inspectability of the mechanical
grooved couplings enabled these installers to verify that every
joint was properly made up, ensuring system reliability without
the additional quality control documentation that would have
been required for weld inspection.
Addressing challenges, adding value. The benefits of
grooved mechanical couplings are being realized on projects in
a range of applications both inside and outside the facility.
In a recent LNG facility expansion, owners encountered a
problem transitioning a carbon steel pipeline from aboveground
to belowground, where it would be buried in unstable soil. Experts
had predicted that over the course of 2 yr, the pipe would
experience 5 in.-6 in. of movement caused by settling, which
exceeded the performance capability of the previously installed
flanged joints. Resolving this problem was simple, using flexible
grooved couplings installed in a series at the transition point.
The mechanical couplings accommodated the dynamic movement,
and because they are easy to install, the joints could be
made up and inspected quickly to keep the project on track.
This solution maximized onsite productivity throughout installation
and will deliver additional gains down the road when
inspections need to be performed or maintenance is required.
Grooved couplings reduce maintenance downtime and,
with a union at every joint, simplify system access. Couplings
are easily disassembled and removed from the joint and can
be reassembled as quickly as the initial installation. The deGas
Processing | NOVEMBER/DECEMBER 2021 7
Hydrocarbon Processing - December 2021

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