146 / 160
March
2017
HYDROCARBON
ENGINEERING
144
in the Netherlands. The company was contracted to
perform pipe design for a new power plant that
would be generating process steam for a chemical
plant.
The scope included creating a DN500 steam line
from the three boilers to the pressure reducing
stations that have connections with the existing
steam piping systems. This also comprised safety lines
to safety valves with blow out lines. In addition,
NEWES was asked to create a DN350 feed water line
from the boiler feed water tank to the boiler feed
water pumps.
All of the systems were to be designed within the
European Pressure Equipment Directive (PED)
according to the Dutch laws for pressure vessels
(RToD). This way, the goal of the project was to design
and install a functional power plant in accordance
with the European legislation, ensuring customer
satisfaction.
The challenge
The three cylindrical boiler connections with low
allowable forces and moments made the steam line
design especially challenging. The distance between
the three boilers was only 7 m and one or two of the
boilers could be out of service at times.
In addition, the main obstacle for successful
design and implementation of feed water lines were
the allowable forces and moments on the feed water
pumps. To overcome these challenges, NEWES chose
to design an expansion loop between each boiler
connection and the main steam line. The system
would be checked according to various design cases,
ensuring compliance with the specified loads and
accuracy of the design.
The solution
NEWES chose to use CAESAR II for all of the stress
calculations in accordance with ASME, EN, and RToD
codes, whilst Intergraph Visual Vessel Design software
was used for the internal pressure calculations
according to ASME and EN codes. First, the piping
system stresses were checked with CAESAR II and the
resulting nozzle loads for the boilers were checked
according to the EN13445 with Visual Vessel Design.
The key benefits realised by using the software
included:
True international code flexibility thanks to the
ability to perform stress calculations in
accordance with all international design codes.
Shortened project time due to efficient and
accurate pipe stress and pressure vessel analysis.
Accurate and correct stress and pressure vessel
analysis.
The future
NEWES will continue to use CAESAR II and Visual
Vessel Design on its upcoming projects for ensuring
design safety. The company commented that one of
the key benefits of using such a software is the ability
to use the created 3D model for computer-aided
design (CAD) engineering.
Case study 3: Larsen & Turbo Heavy
Engineering
Background
Larsen & Turbo Heavy Engineering (L&T) was assigned
the design and manufacture of five large diameter,
high pressure columns for a refinery facility in Liwa,
Oman. The project required complete mechanical
design and fabrication per ASME Sec VIII Division 1
and 2 codes and included the nozzles, platforms,
internal components, pipe loading, and other
elements. The columns had diameters ranging from
2.9 m to 4.5 m and lengths of 26 m and 30 m.
The challenge
Designing such large-sized columns while addressing
the many design conditions of the client and
following the international code requirements to
ensure safe operation can be very challenging. In
addition, the contract delivery date was very
stringent.
Meeting deadlines is important for manufacturers
if they are to satisfy the client’s requirements and
build trust for future business opportunities. With the
use of a modern engineering software, L&T was able
to avoid delays at the start of the project that would
have impacted the whole subsequent manufacturing
cycle time.
This would cause a loss of money and lower the
level of trust of the client in the firm’s capabilities.
The large complex design benefited from the
PV Elite
®
3D model, which allowed for checking for
clashes and other issues before preparing the
drawings. L&T could then finalise the locations of
nozzles to accommodate piping requirements.
The solution
L&T designed complete equipment with all related
design conditions and represented supporting
calculations for review by the client and any
third-party inspectors assigned to that task. L&T was
able to deliver client requirements within the planned
timeline and receive the milestone payments from the
client as scheduled.
PV Elite provided fast and convenient calculations
and control of the various revisions required by the
client, saving time and expense. The company was
able to reduce design time with the user-friendly
interface and accurate output.
Conclusion
As the experiences of On Line Design Engineering,
Newes and L&T show, smarter software solutions can
significantly improve the quality of the overall
analysis of heat exchangers, pressure columns, and
pressure vessels, whilst contributing to an overall
improvement of design efficiency.