Hydrocarbon Processing - March 2021 - 71

Maintenance
and Reliability
B. FORBES, AMETEK, Berwyn, Pennsylvania

Strategies to minimize piping thermal maintenance
system cost without compromising performance
Where process fluid must be maintained within a certain operating temperature window, the piping will likely
require the application of a thermal maintenance system. Thermal maintenance
systems can utilize a broad range of technologies-from bare tube tracing to fully
jacketed pipe. However, regardless of the
technology employed, engineering must
be performed to design the system. The
approach used for the engineering and
design of the system can have a dramatic
impact on the cost. This article presents
four strategies for minimizing the total
cost without compromising performance.
The strategies are:
1. Match the heating technology
to the application
2. Optimize the heating circuit
lengths
3. Optimize the utility infrastructure
4. Structure the bid process to
reward optimization.
In addition, three real-life examples
are presented that demonstrate the actual
savings that these strategies can achieve.
These examples are:
* Example A showing the benefit of
Strategies 1 and 2 combined
* Example B showing the benefit of
Strategy 3
* Example C showing the benefit of
Strategy 4.
While much of this discussion centers
around steam heating systems, the same
principles apply to other heating fluids
and cooling systems.

tenance system. The most common considerations are:
* The purpose of the heating
system: Liquids must often be
maintained above a freezing point.
However, for vapors, condensation
within the piping is often a primary
concern. In some applications, a
pre-heat or recovery (melt-out)
condition is the primary concern.
* The acceptable temperature
window: Some processes must
simply be maintained above or below
a critical threshold. Other processes
have both an upper and lower bound
that must be considered.
* The available temperature
differential: Some applications
afford a large " temperature delta "
that enables even a relatively poorly
performing technology to be used
successfully [e.g., maintaining a pipe
above the water freezing point (0°C)
using 10 barg steam (184°C)].
Other applications provide very
little " temperature delta " and require

a very robust heating system
to ensure success [e.g., maintaining
a pipe at 180°C using the same
(184°C) steam].
Properly matching the heating technology to the application is key to reducing
cost. An over-performing heating technology will cost more than a performancematched technology. Conversely, applying an under-performing technology will
necessitate the use of additional tracing
runs and heating circuits, which will drive
up the cost of the utility components. A
properly matching technology will optimize both costs: (1) the heating technology itself will cost no more than what is
necessary to achieve the purpose and (2)
the utility infrastructure requirements will
be minimized along with associated costs.
Many tracing technologies are available on the market. A true technology
partner can help you select the best option without bias to any one solution.
FIG. 1 is one example of a robust range of
heating technologies.
Technology 1a provides an eight times

Strategy 1: Match the heating technology to the application. Different

processes require different considerations in the design of the thermal main-

FIG. 1. One example of a heating technology suite.
Hydrocarbon Processing | MARCH 2021

Hydrocarbon Processing - March 2021

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