Hydrocarbon Processing - April 2021 - 58

Engineering and Construction
to ensure that the plant's equipment and facilities were still fit
for service. Fitness for service (FFS) purpose or mechanical integrity is a set of quantitative methods used to determine the integrity and remaining life of degraded components and to help
operators make run-or-repair decisions.
Project managers and engineers visited the plant site for an
initial evaluation. From visual inspection, various fabrication deficiencies and concerns were flagged by the team. These observations included the following:
* Standard products for various equipment components
(e.g., nozzle flanges, blind flanges, studs and bolts)
were not used (FIG. 2).
* Geometrical configurations (thickness and diameter)
for various equipment components did not comply
with that of standard products.
* Mismatch of equipment details with that shown
in as-built drawings.
* Defects and cracks in equipment were clearly visible.
* The subpar quality of fabrication, welding and
repair work were clearly noticeable (FIG. 3).
Based on these observations, an adequacy check of the plant
and its equipment was carried out based on available drawings,
documents and site survey reports. Most of the facility and equipment failed this adequacy inspection, based on the following:
* Code of construction (ASME vs. local standard)
* Operation methodology
* Source of equipment
* Fabrication quality
* Product standardization.

FIG. 2. Standard products for equipment components were not used.

Most of the equipment was fabricated and operated as per
local codes and plant operation methodology. These are based
on FFS and do not meet the requirements or codes mentioned
in the fabrication/as-built documentation. The client who purchased the plant decided to retrofit/revamp the existing plant
and to increase capacity to make retrofitting economically viable.
In a separate project, a Middle Eastern client purchased
equipment from a Western country and transported it to the
proposed site. Most of the equipment was retrofitted/revamped
to make it suitable for the design and operating conditions of the
proposed plant. This was a challenging management decision,
as many cost factors involved in retrofitting (such as the cost of
existing equipment, logistics, transportation, retrofitting and reinstallation) needed to balance out the costs of new equipment
fabrication and installation. The risk involved in anticipating the
cost of retrofitting vs. new equipment installation was substantially high due to the uncertainty in estimating all types of cost
in retrofitting. FFS relies on comparing the demand on the degraded component/equipment (e.g., the load exerted in-service
in the form of pressure, temperature, weight, vibration and flow
transients) to the components' capacity to sustain demand.
With greenfield plants being capital intensive and having
longer construction timelines, retrofitting an existing plant and
equipment can be a viable option to meet product demand.
Operating companies must have proper planning and documentation to greenlight a retrofitting project to meet current
market demand and to maintain a grasp on the latest technologies and environmental legislation. Some of the key factors to
consider include:
* As-built drawing test reports and material certificates
* Periodical equipment health check reports during
planned maintenance and inspections
* Remaining-life assessments for equipment, based on
present operating and design conditions
* New regulations and legislational changes
* Planned capacity/efficiency improvements
* The quality of the finished product.
All these factors must be assessed meticulously before greenlighting a retrofit on an existing plant. Other factors appear
when equipment modifications, relocations, reinstallations
and testing are carried out. These costs can impact an owner's
planned retrofit project budget. Technical risks include:
* Specificity of works and experience of engineers/designers
* Primary parties involved in the project (such as fabricators
and construction contractors)
* Technology used and compatibility between new design
specifications and the original design
* Technical safety margins on upgraded machines
* Conservation measures during standstills
* Logistics and security on working sites.
Various equipment codes boilers, pressure vessels, storage
tanks and pumps also need to be verified during a retrofit project.
Takeaway. Retrofitting a plant or existing equipment is a viable

FIG. 3. The quality of fabrication, welding and repair was subpar.

APRIL 2021 | HydrocarbonProcessing.com

option for oil and gas operators, as well as for chemical manufacturers. All parties must efficiently optimize their workflows to
optimize costs and to increase the quality of the facility's products, while adhering to regulations. The items presented here will
help operators to minimize risk during retrofitting operations.

http://www.HydrocarbonProcessing.com

Hydrocarbon Processing - April 2021

Table of Contents for the Digital Edition of Hydrocarbon Processing - April 2021